Scotch-Brite(TM) Cut and Polish Unitized Disc, 4 1/2 in x 7/8 in 7A MED, 5 per case Long lasting, aggressive disc for tough blending and finishing applications. A layered, durable unitized disc construction. Hard 7 density. Abrasive mineral: Medium grade aluminum oxide. Color: Tan MOS: 11,000 RPM