The abrasive disc is designed for machine grinding. It is equipped with a hook-and-loop fastener, allowing it to be installed on a rotary-vibratory sander. Special holes (various arrangements and numbers of holes are available) allow dust generated during sanding to be removed through the sander's suction channels. The abrasive grain is made of aluminum oxide. The discs come in two types of coating: open and semi-open. The specially reinforced paper has very high tear resistance. Two layers of binder made from special synthetic resins excellently hold the grain and prevent it from chipping.