Friday, May 21, 2010

Basics in Silat Sera - Laws and Principles

A series of articles by Todd Ellner and Tiel Ansari, from Guru Plinck's website:

Laws and Principles of Sera

These can be loosely interpreted as "rules for doing things." The items listed here can be seen as rules for correct movement: technique that conforms to these rules will be efficient and effective. They can also be seen as tactical rules that maximize the Sera player’s chances of success in a fight.

A distinction should be made between laws and principles. Laws are ccommon to all situations, whereas principles offer choices. For example, Weapon Before Body/Body Before Weapon- can be considered a principle, because the Sera player chooses which to use depending on the needs of the moment. On the other hand, Fighting is Positional is true in any situation, and therefore qualifies as a law.

Laws can be broken under certain circumstances. (Some of these circumstances are mentioned in the discussion of the individual laws.) But it’s only after you understand the law and the reasons for it that you become able to judge when, how and why to break it. Therefore, as a beginner, you should regard the laws of Sera as absolute. In the following discussion, we will mostly not distinguish between laws and principles.

Sera’s principles are highly interdependent, and it’s therefore difficult to present them in any particular order. We’ve chosen to present them in a way that emphasizes the relationship of each principle to the sequence of events that might take place in an idealized encounter between two Sera players. Notice that the principles most closely related to Entering, which occurs at the beginning of an encounter, are usually the last to be trained. Understanding of these principles comes through sparring, and as explained below, sparring is not part of beginner training in Sera.

One of the goals of Sera practice is to condition the body of the student to move in accordance with the principles. As with most physical training, it’s initially the responsibility of the teacher to correct the student’s movement: "You’re not separating your bases", "You left the low line open" "Where’s your opposite lever?" These corrections have to be applied to all aspects of training: djuru practice, two-person drills, basic technique, and eventually sparring. (The knowledgeable student will observe that many of the core drills of Sera are not only in agreement with the principles, but designed to help ingrain them.) No part of Sera is exempt.

Initially, the student learns the principles associated with Positioning and Finishing. Over time, these principles become habitual, and the student no longer needs to think about each motion to ensure that it’s correct with respect to them. Sparring in Sera is usually deferred until this stage, because the student will now reflexively respond to a threat with correct movement. If sparring is introduced too early, whatever erroneous habits the student still has will be further ingrained.

It’s important to understand that "correct movement" does not imply that there’s a single correct response to a given situation. Any movement that gets you closer to your goal (whatever that happens to be) is correct. Movement that conforms to the principles will be tactically advantageous and mechanically efficient.
Fighting is Positional

"Positional" refers to the position of your body and limbs relative to those of your opponent. This relationship determines what options each of you has at a given moment. One of the strategies of Sera is to gain positional advantage, i.e. to create a position in which your opponent’s options are limited and therefore predictable, but which does not restrict your options.

At long range, we gain superior position through footwork. The ideal is to place the opponent in a position in which we can predict exactly how and when she will respond to an entry. The geometric relationship determines what tools the opponent can bring to bear. The distance determines the timing of the opponent’s response: she will strike when the attacker comes within range.

At arm’s reach or less, a superior position is one which gives you control of the opponent’s body. In this range, position is gained by a combination of good structure and sensitivity. Good structure, for the purposes of this discussion, includes footwork. At this range, footwork becomes one of several factors.

Close range is extremely dynamic, in the sense that minute changes in one person’s body alignment, balance and limb position can drastically alter the other’s "optimal" tactics. Therefore there is no single, static "good structure" that will serve throughout the encounter.

Sensitivity helps the Sera player create appropriate structure in response to a rapidly changing situation. The Sera player must maintain the criteria of good structure while accomplishing various other tasks, such as striking and throwing. This doesn’t imply that the Sera player consciously thinks about structure while fighting. Good structure comes from following the principles associated with Positioning, and as stated in the Introduction, these should have become instinctive by the time the student is introduced to sparring.

Guru Plinck says: "Understanding is the transition between stances and position." "Stances" here has a static connotation. The beginning student learns correct stances, because it's necessary to start somewhere-- as Guru Plinck also says, "You have to learn to stand before you can learn to walk". But position is dynamic, and as the student gains understanding, position replaces stance.
Separate Your Bases

"Base" in this case refers to the shoulder girdle and feet. In application, this principle might be expressed as follows: when moving your feet (sweeping, kicking, stepping), do not rotate your shoulders; when moving your upper body (powering a strike with upper body rotation, unbalancing your opponent for a throw), your feet should not move.
This principle exists because you need a stable base from which to generate power. There is an exception: when being completely evasive (for instance, getting out of the way of an incoming attack), it’s okay to move both bases at once, because you are not applying power and have no need to generate any.
Base, Angle, Leverage

These are the three components needed to set up a Sera-style throw. Most throws can be executed using two out of the three, but for safety’s sake, you should try to have all three. Successful execution of many Sera throws depends on precise use of these components. Though the terms are now in wide use, it's important to understand exactly how they are defined in this context.

"Base" in this context means the strength of the connection of your upper body to your lower body, and of your lower body to the ground. Often (not always) the placement of your feet will prevent your opponent from moving his feet to adjust to the forces you’re applying to his upper body. Your djuru stance provides a good base for throwing.

"Angle" means force applied along the weak angle of your opponent’s stance. Every stance has a weak angle, usually more than one. You can usually find one of your opponent’s weak angles by pulling one of her arms toward the point of a triangle on the ground, the other two points of which are defined by her feet. Correctly applied, angle should bring the opponent’s weight toward the foot that you plan to sweep, because sweeping an unweighted leg will have little or no effect on the opponent. Also, the more weight your opponent has on that leg, the less able she will be to move it and get away from the sweep.

"Leverage" means force applied to your opponent’s body in a different direction than the angle, and in a different direction than the force applied by the sweeping foot, creating Opposite Levers. In combat, leverage is applied as a strike— in a class setting, it’s usually applied as pressure.

The three components can be initiated in any order, but once a component has been initiated, it should be maintained until the throw is completed. You should not, for instance, give up angle in order to apply leverage, though the weak angle may change as the opponent’s balance shifts. The net effect of angle and leverage is to move the opponent’s center of gravity off the supporting foot, after which gravity takes over.

In the classic sapu, the sweep is followed by the upper-body unbalancing, while in the classic beset the order is reversed. In application, either order is permissible with either type of sweep. It's important to stress that, if unbalancing the opponent's body requires moving your upper body, this cannot be done simultaneously with the sweep. To do so would violate Separation of Bases.

Control at the Root

One of the favorite strategies of Sera is to control the movement of the whole body by controlling the spine. If the spine isn’t directly reachable, Sera players do the next best thing by controlling limbs as close as possible to where they join the spine. Thus, the arm should be controlled above the elbow and the leg should be controlled above the knee.

This also reduces the opponent’s ability to maneuver. For instance, if you hold an opponent’s arm at the wrist, he can still strike with the elbow or shoulder of that arm, or turn to bring the other arm into play. If you pin his upper arm, he cannot strike with the elbow, fist, or shoulder, and if you are on the outside, he cannot bring the other arm into play except by a spinning move.

Another reason to attack the root is that it is the part of the limb that moves the slowest. Intercepting a fast punch at the hand requires extremely good timing and hand speed. However, even on a very fast punch, the shoulder hardly moves at all. Stopping the motion of the shoulder will prevent the punch from reaching its target. The same applies to the hip, in the case of a kick.
Weapon Before Body for Speed/Body Before Weapon for Power

For a given technique, there is a tradeoff between speed and power. (It’s a mistake to assume that more powerful techniques are necessarily slower.) To deliver a technique at full power, the body should lead the motion. This is almost always slower than the same technique delivered without body involvement.

To enter, we usually need to deliver fast strikes to disrupt the opponent’s timing and allow us to move the body into close range. Full-power techniques are used as finishing shots, when the opponent is off-balance or already damaged, and timing is less critical.
Always Have Backup

Backup is one of the most fundamental concepts of Sera, and also one of the most complex. In the most general sense, the backup concept is that you should expect each technique to fail and be ready to follow up with something else. However, launching one independent strike after another may not be the most efficient way to accomplish this.

In Sera, the concept of backup implies that each technique should set up its own follow-up options.

One of the simplest formulations of this concept is the rule stated by Pendekar Paul de Thouars: "One hand never goes into battle without the other." This rule is exemplified in the djurus by the reinforced punch, in which one hand backs up the other. The reinforcing arm physically supports the lead arm, creating a structure like a brace, which can withstand a great deal of incoming force. It also allows the entire upper body to be involved in powering the strike, if desired, rather than just the arm muscles. In addition, the reinforcing hand is immediately available for a follow-up.

This should not be construed to mean that the hands are always right next to each other. Backup and reinforcement can mean a variety of things. Simple proximity and direct reinforcement are useful training tools for the beginner to give him or her a simple physical application to illustrate the concept.

Within this simple geometric relationship, either hand can be either hard or soft, embodying a number of different attitudes. "Hard" and "soft" are terms that mean many different things to different martial artists. The usages defined below should be regarded as strictly local: they may not be valid elsewhere in the martial arts world, or indeed, elsewhere on this page. Even in this context, "hard" and "soft" can imply a number of different things.

A physical interpretation might be that a hard hand is prepared to deliver a strike: if the strike is a punch, the hand should be clenched into a fist. In contrast, a soft hand is open and relaxed, able to monitor or pin one of the opponent’s limbs, deliver a strike, clear an obstruction, etc. In a more tactical interpretation, a hand that is hard is committed to a specific objective. A hand that is soft is able to improvise in response to a changing situation.

Another way of looking at it is that "hard" designates the hand that is contributing the most force to the strike, even though it may not be the one that is actually making contact. This is deceptive, because the opponent will usually expect the line of the strike to be determined by the striking hand. If the strike is in fact being guided by the rear hand, the line will be subtly different. (See "Lead hand soft/reinforcing hand hard" below).

We have the following possible soft/hard combinations, with examples of how they might be applied:
Lead hand hard/reinforcing hand soft-- Front hand delivers a strike, rear hand can deliver whatever follow-up is desired.
Lead hand soft/reinforcing hand hard-- Pressure from the rear hand can be used to slightly change the angle of attack of the front hand, circumventing obstacles.
Lead hand soft/reinforcing hand soft-- Neither hand is committed to a specific course of action, leaving the greatest number of follow-up options.
Lead hand hard/reinforcing hand hard-- This combination is tactically risky, because it restricts the sensitivity of both hands and leads to too much reliance on strength.
The hands can back each other up in many ways besides one reinforcing the other. Some of these, with examples, are:
Same line, same weapon-- Two rapid-fire hits are delivered in the same line: if the first one is blocked, the second one will usually get through. (Note: the first strike should not be regarded as a "fake". If the first strike is not blocked, it should hit. This is a general rule of Sera.)
Same line, different weapon-- Closely related to reinforcing. If the lead hand is blocked, the rear hand immediately strikes in the same line.
Same weapon, different line-- The rising punch in Djuru 2 is a good example of this. The opponent directs a countering technique to the line he expects the punch to be on, only to find that it’s not there.
Cover and hit-- The backup hand goes slightly ahead of the striking hand and clears away any obstruction that it finds.
Bait and switch-- Expect the first strike to be blocked; the contact signals an immediate switch to a backup strike delivered in a different line, usually with a different weapon. (Again, note that if the first strike is not blocked, it hits.)
Backup need not be restricted to one hand backing up the other. Here are some more backup concepts:
Anatomical-- Any body part can back up any nearby body part. For example, if your punch is blocked, it is easy to simply fold forward and strike with the elbow of the same arm. Or, you might step in and pivot to strike with the shoulder of the same arm.
Upper body/lower body-- Another formulation of the backup concept was stated by Pendekar de Thouars as "Hands don’t go into battle without feet." (It could just as easily be "Feet don’t go into battle without hands".) If you find your arms tied up, consider delivering a kick or knee or using footwork to change the position and give yourself more control. If your lower body is being attacked with a sweep, you can use your upper body to support yourself.
High/Low, Inside/Outside, Left/Right

A useful way to think about Sera technique is to classify it in terms of root motions. You can generate whole families of techniques by applying the same root movement to your opponent from different positions. Guru Plinck states this as follows: "What you can do high, you can do low. What you can do inside, you can do outside. What you can do left, you can do right."

The beset family is a good example. Beset luar and beset dalem are the same motion, applied either from inside or outside. (Note that in beset dalem, you are positioned outside the opponent’s arm but inside her foot: in beset luar this relationship is reversed. These are examples of Opposite Levers.) Both throws can also be done as low sweeps. And obviously, both can be done whether the opponent is in a right or left lead. In all cases, the root motion is the sweep.
Take the Line

Blocking is not encouraged in Sera. A block may keep you from getting hit, but generally does no damage to the opponent (unless you train in a style that conditions heavily and delivers destructive blocks). More importantly, blocking puts you a beat behind and, because action is faster then reaction, it’s very difficult to catch up. The common "block, then hit" strategy is likely to lose against an opponent who is your equal in speed, or even slightly slower.

Instead of blocking, Sera players hit. The hit has the effect of blocking the incoming strike, but it’s important that the goal is not to block: the goal is to hit. The blow is directed in such a way that it covers the incoming line. This is what is meant by "taking the line". If the blow reaches its target, it will have blocked the incoming strike.

Taking the line also brings your tools deep into the opponent’s territory, where you can begin to gain Control at the Root over his tools and limit his options.
Cover High and Low

Your opponent is likely to launch a mixture of high-line and low-line attacks. It behooves you to cover both lines at all times. In this context, "cover" does not necessarily mean "physically occupy": it means that you have something available to respond in that line.

An obvious way to accomplish this is to cover high line with one hand and low line with the other. For example, in the context of reinforcing, the Backup hand can be thought of as covering the high line if the strike is being delivered low, and vice versa. A low stance is very helpful here, because it means that your upper body tools can cover more of the target area. When standing upright, most people’s fingertips reach about to mid-thigh; in a crouch, your fingertips can easily reach to the knees or below.

Less obviously, a hand can be used to cover high line and the elbow of the same arm can cover the low line. Or a hand or elbow can be used to cover low line and a shoulder can be used to cover high line. These approaches can be very useful at close range.

Hands and arms can cover the high line and legs can respond in the low line. This is one of the reasons single-weighting is important: one leg or foot is always free to respond to a threat.
Control Center

The center plane (often referred to as the center line, or just the center) is the plane that connects the vertical axis of your body to the vertical axis of your opponent’s body. On the human body, most of the attacking tools are located at the periphery (knees, fists, elbows, feet: the head is a major exception). But many attacks tend to be aimed towards the center, where the preferred targets are located (face, throat, solar plexus, groin). Such strikes are seen as entering the center plane from one side or the other, and can be prevented from connecting by controlling access to the center.

In Sera there are several ways this is accomplished.
Occupying center This is usually done with a strike: the reinforced punch is a good choice for this, as it is structurally strong enough to withstand a collision with an incoming blow, and also protects against strikes coming in from many different angles.
Cutting center Also generally done with a strike, this is an example of Taking the Line. Cutting center differs from occupying center in that the strike is delivered at a slight angle across the center plane, instead of within it. This gives you the option of crossing to monitor and control tools on the far side of the opponent’s body. Cutting is the most effective approach against a hook or horizontal elbow: in this case the strike is aimed at the shoulder (Controlling at the Root).
Yielding center Against overwhelming force, center can be yielded by rotating the body parallel to the attack, allowing it to slide past. This can be viewed as an example of an upper-body Alleviation.
Clearing center An example of this is seen in the first move of the first djuru. Clearing center is closely related to cutting center, but is less aggressive and involves more Alleviation of the incoming strike.
Repositioning center This generally involves footwork, such as stepping off the line of an incoming attack. Notice that purely evasive moves are not a favorite in Sera: ideally, repositioning should gain you a better position in addition to keeping you from getting hit.
Offsetting from center If you have occupied the center plane, your opponent may try to strike slightly to one side or the other. You need to be prepared for both possibilities. But if your occupying tool is offset to one side, you make it much more likely that your opponent will attack to what he sees as the open center.
In practice, a Sera player will often use one or more of these in combination. For example, she might clear center and create an offset to guide the opponent’s next move. Or, she might deliver a strike that cuts center while repositioning herself out of the line of an incoming attack.
Right Tool for Right Range

The most basic application of this principle is one that many martial artists are familiar with: Use long weapons at long range, because short ones simply won’t reach; use short weapons at close range, because they take less time to deliver, and long ones are more easily jammed at close range. For instance, most boxers will rely on the jab and cross at long range, but at close range will use more hooks and uppercuts.

Broadening the definition of "tool" points up some of the other differences between ranges. For instance, position is extremely important at both ranges, but is gained in different ways (see Fighting is Positional).

At long range, you rely on vision to keep you informed of what your opponent is up to. At closer ranges, you must rely more and more on sensitivity. (Try to imagine a blind kickboxer, as compared to a blind wrestler.) The same is true of our opponent. At long range, we deceive our opponent by misleading her perception of distance, timing or position through the visual sense. At close range we mislead her senses of contact, balance and proprioception.

Long range and close range also require different attitudes. At long range a fighter should be eager to close, but not so eager that he rushes in blindly: he must be patient enough to create an opportunity to enter safely. Close range requires alacrity and commitment. It should be noted that both ranges require detachment, complete attention and intensity. Cultivating this set of emotional attributes should be looked on as a life-work, not a prerequisite.
Opposite Levers

"Always have an opposite lever"-- Pendekar Paul de Thouars

The more different unbalancing forces you apply to your opponent, the more difficult he will find it to compensate. Most people can keep their balance pretty well if a single force is applied to them. If two forces are applied, it becomes much harder, and is even harder if the two forces are not symmetric (not directly opposite from one another). The Base, Angle, Leverage formula with sweep applies three forces to the opponent, all in different directions.

If you pull or push on your opponent’s upper body, his natural reaction will be to step towards or away from you to keep his balance. There are two common ways of preventing this. One is to bring a substantial part of the opponent’s weight onto the foot he would naturally step with, so that he can’t lift it without losing his balance. The other is to trap the foot to keep it from moving. The "Opposite Levers" principle helps to create these traps. For instance, if you are pulling your opponent to your left, you should be planning to sweep his foot to the right, and this places your sweeping foot in the correct position to block him from stepping even if you don’t execute the sweep. ("Left" and "right" here shouldn’t be interpreted too literally, as the angle direction and sweep direction aren’t directly opposite from one another.)

A related concept is that people cope with steady forces much better than they cope with changing ones— this is sometimes stated as "People make better speedometers than accelerometers." This is why many throws become more effective if the directions of the forces being applied change in the course of the throw.

The throw known as puter kapala combines all of these concepts. The head and arm are used as opposite levers. As you bring the head towards you, the opponent’s weight shifts onto his front foot, so that he can’t lift it without losing his balance. (You can also trap the opponent’s front foot with yours, but it’s usually unnecessary if you are applying correct angles.)

Puter kapala is often described as a spiral or circular throw: the head is brought towards the ground in a smooth spiral. In this approach, the forces being applied are smooth and steady. An opponent with some sensitivity will extrapolate the motion and adjust to it. Puter kapala becomes much more effective if the forces are applied in a series of short jerks at different angles.
Long-Range Weapon Before Short-Range Weapon

This principle helps to create the efficient entries that are one of the strengths of the Sera style. Long-range strikes are used to disrupt the opponent’s timing and create an opportunity for the attacker to move to close range and bring to bear the more powerful short-range weapons, and eventually execute a throw. Entering with a short-range weapon is much riskier, because the opponent is in full control of his faculties and can counter easily.
Alleviation

One of the strategic assumptions of Sera is that our opponent is stronger than we are. Therefore, we do not resist force with force. One option is to evade the incoming force altogether: the drawback of this is that it does not necessarily improve our position. Alleviation refers to a dissipation or diversion of the incoming force with minimal movement and contact that is perceived by the attacker as very light.

In Sera there are several modes of alleviation, and most can be used in combination with one another. It's important to practice them independently. One should also keep in mind that more alleviation isn't necessarily better, and that upper-body-based alleviations are generally faster than footwork alleviations.

In tool-only alleviation, a tool (usually upper-body) is used to deflect the incoming strike. No other part of the defender’s body moves. Conversely, in upper-body alleviation, the upper body is rotated parallel to the attack, and no tool is used. Footwork can be used to reorient the upper body, but this will tend to be slower, and should not be resorted to unless it gains some other advantage.

Footwork can be used to alleviate by itself. Against an incoming attack, a Sera player can move along the circumference of an imaginary circle centered on the opponent, to get off the line of attack without changing the distance. Or, he can move out or in along the radius of the circle so as not to meet the attack at its point of maximum power. These effects can be combined in a step along either a tangent or a chord of the circle.

A level change can also be used to alleviate, removing the target from the line of attack without changing location.
There are two somewhat more specialized modes of alleviation that deserve mention here. In the mode known as "receive and give", the Sera player absorbs the incoming energy, storing it mechanically in the elastic muscles of the midsection, and then uses the stored energy to power a return technique. To an onlooker, it appears as if the player recoils slightly and then explodes forwards.

"Bypass and enter" describes an alleviation in which the player deflects the incoming blow and advances, leaving the deflecting tool where it is. This is a deceptive move. Since the contact point remains still, the opponent is (briefly) prevented from realizing that the player has entered.
English

Guru Plinck uses the term "english" by analogy with pool, where english refers to spin placed on the cue ball. Here, english means a circular, corkscrew, or rotating movement. An example of motion with english can be seen in the first move of Djuru One, where the wrist is rotated through its entire range of motion.

Notice that if you are moving forward while executing a circular motion, it becomes a three-dimensional corkscrew.

Genuinely two-dimensional circular motions are rare in Sera, but the terms "circular" and "corkscrew" are sometimes used interchangeably.

English is frequently used in Alleviation with a tool, to soften the contact and deflect the incoming strike. In one way of doing this, the alleviating tool executes an english movement such that the strike is nearly tangent to the circumference of the circle described by the english. The direction of rotation is almost parallel to the strike. This minimizes the opposition between the force of the strike and the alleviating force.

Another use of english is in the type of Alleviation referred to as "Receive and give". In this case it’s the body— specifically the hips— that execute the english motion, absorbing the incoming force and storing it on the first half of the movement and releasing it towards the opoonent on the second half.

This suggests that english can also be used to generate power, and indeed that’s the case. Body english involves most of the major muscle groups and thus can generate far more power than a tool alone can provide. It should be noted that techniques powered in this way will be slightly slower than tool-only techniques: see Weapon Before Body/Body Before Weapon.

English can also be used to generate power at the tool-only level. The forearm is a common striking tool in Sera. Consider the forearm as a cylinder: if it is rotated around its long axis, the outer surface is the part that rotates the fastest. This rotation can be added to a forearm strike to create a shearing effect.

One final note on english: unlike a corkscrew, the radius of an english movement need not be held constant. Such a motion might start very small, to efficiently alleviate a strike, and expand to cover the opponent’s torso (Controlling Center). Or it might start as a large arc, Taking the Line of an incoming attack, and spiral in to a strike.
Step With a Purpose

Every step you take in an encounter should accomplish something: never step just for the sake of stepping. There are many purposes that a step can have. Footwork is how you control distance; through distance, you control the timing of the encounter. Footwork is also how you control position; through position, you control your opponent’s options.
Most of the Sera sweeps and kicks are derived from the movements used in walking. Because of this, these motions are very natural and easy to learn – after all, you walk hundreds if not thousands of steps every day. Also, a step can be converted into a kick or sweep at any time, if a suitable target is available. So the purpose of a step could be to deliver a kick or sweep.

Footwork is what moves you from long range to close range. A good Sera entry should lead directly to a throw. This implies that the last step of the entry should accomplish at least two things: it should bring you into throwing range, and it should create a strong Base from which you can execute the throw. It may also serve to deliver a kick, knee or sweep; trap the opponent’s foot to keep him from adjusting his balance; add power to the delivery of an upper-body strike; or help pull the opponent off-balance.
Move Less, See More

At close range, this could be restated as "Move less, feel more." It is true in many martial arts that a good structure will defeat a flurry of techniques. Unnecessary movement is a waste of effort and time that an efficient martial artist would do well to avoid.

Movement also implies temporary loss of structure: even if you are in transition from one good structure to another, there is a space of time where you are not in good structure. During that time, you cannot capitalize on any opportunities that may appear, and you are vulnerable to attack.

Elsewhere we discuss the idea of dividing time into full beats and half-beats. A movement creates at least a partial beat, and this is a unit of time that you will find extremely difficult to subdivide. Put another way, if your opponent is alert and attacks you in the middle of a movement, you will find it hard to respond until you have finished your motion.

Moving divides your attention, making it more difficult to maintain your focus. It can also telegraph your intentions. Purposeless movement tends to fall into a rhythm, which helps your opponent predict what you're about to do.

2 comments:

  1. It is a informative blog.. Got to know many healthy practices.. I would like to go for it..

    Concrete Core Drill

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  2. Very impressive! Thanks for sharing Steve.

    ReplyDelete