The United Abrasives/SAIT Saitech cutting wheels (Type 27/Type 42) are made to go on an angle grinder. The wheels high performance, ceramic aluminum oxide grain, is designed to outlast standard aluminum oxide wheels. The wheels uniform, high density grain structure is extremely durable and self sharpening. United Abrasives/SAIT wheels are reinforced with highest quality fiberglass for maximum safety and performance. Proudly manufactured in the USA.