High performance, ceramic aluminum oxide grain.Very uniform, high density grain structure is extremely durable and self sharpening for long life and cooler cut.High Performance.Combines fast cutting with extremely long life., Type 1/Type 41 shape for square, burr-free cutting.Externally reinforced with fiberglass layers to provide ultimate safety in a thin wheel.Type 1/Type 41 Cut Off Adapter (1/4" shank adapters for wheels up to 3" diameter) available in Accessories. Cut-Off Adaptor.