The Metalab Pinchless Copper French Link Continental 4 Ring Gag Bit features a hollow, stainless steel mouthpiece with a copper French link designed with the Pinchless System. The Pinchless system was invented by, David Robar, an American trainer. Pinchless eliminates the pain in the horse's mouth and it's anticipation of this pain. Due to an internal mechanism both sides of the bit can move independently, avoiding the chance of pinching the horse's tongue and lips. Pinchless helps with a better communication between you and your horse, less stress for your horse and a closed and relaxed mouth.