Fiber Disc, Abrasive Type Coated, Abrasive Material Aluminum Oxide, Backing Material Fiber, Backing Weight Not Applicable, Grit 24, Overall Diameter 4 1/2 in, Series 381C, Coating Coverage Closed, Maximum Operating Speed 13,300 RPM, Connector Size 7/8 in, Connector Type Unthreaded Hole, Color Brown, Grade Coarse