2" Surface Preparation Quick Change Discs by Black Hawk Abrasives are designed for removing scratches, discoloration and other blemishes caused by earlier stage coated abrasive sanding. These discs are capable of buffing, finishing or just general surface conditioning in preparation for final stage polishing. Each 2 inch surface prep quick change discs is made with high quality non-woven, compressed nylon mesh, impregnated with either Aluminum Oxide (red) or Silicon Carbide (gray) abrasive grains. These discs are similar in nature to unitized discs or deburring wheels with the difference that they are lower density and thus more conforming to the work piece. Their conformability and small size make them ideal for detail work, jobs in hard-to-reach areas or work on irregular shaped pieces. Each 2” surface prep disc comes with a durable plastic, type-r male roll on backing which easily screws into a female quick change backing pads. These discs are made to be used with a backing pad on a die grinder, drill or air grinder and are especially effective on steel, aluminum, stainless steel and nonferrous metals. The Red - Fine, Aluminum Oxide surface prep discs are particularly effective at cleaning, blending or finishing stainless steel. The Grey – Ultra Fine surface prep discs excel on wood or composites as well as producing a satin finish on aluminum and polishing other metals.