3M 237AA Trizact Bands, 1/2-Inch x 1-Inch, 400 Grit

3M's Trizact material is an embedded aluminum oxide abrasive in random pyramid shapes on the surface that gives a quick, fine grind on the surface of the glass. Perfect for cleaning up areas that have already been ground with rougher grits. These will generate heat very quickly on the glass, so be very careful using them for an extended period to avoid creating micro-fractures in the glass surface.