Special aluminum oxide grain.Extremely fast burr-free cutting with long life.Exceptional Performance.So unique it has a patent., Unique, thin Type 27/Type 42 shape can be used on all angle grinders in accordance with ANSI B7.1.Special aluminum oxide formulation offers the fastest cutting, longest lasting thin wheel.Externally reinforced with fiberglass layers to provide ultimate safety in a thin wheel.Proprietary bonding system allows for faster, burr free cuts.Reusable 5/8-11 adapter for use on Type 27 / Type 42 reinforced wheels with a 7/8 arbor, and a maximum diameter of 5" and a wheel thickness of .045" to 1/8" is available in accessories. Part #95055.