I was exclusively designing professional Saws for a major power tool manufacturer for several years. Prior to this, I was part of a team that was designing miter saws and table saws and was closely involved with designing both products. I am also a skilled user of power saws, having completed many construction projects using them. I also led teams that designed professional saws for a major power tool manufacturers. I am very familiar with the common safety equipment on power saws, the regulatory requirements around such equipment, and the common limitation of such equipment when a saw is in use. The main piece of safety equipment is an articulating guard that opens as a cut is started. There are requirements about the strength of the guard and the amount of exposure that there can be to the blade. Guards have weaknesses in that they must open to make a cut. Also, users must remove or shift the position of the guards when changing blades, and some systems are more forgiving than others. In addition to the guard, the strength and size of the fence behind the material being cut is very important. Poorly supported material can kick back during operation. Finally there are usually some indications on the saw and in the manual that the operator is to keep hands a fixed distance away from the blade at all times.