Quick-Change Sanding Disc, Abrasive Type Coated, Abrasive Material Aluminum Oxide, Backing Material Polyester, Backing Weight YF, Coating Coverage Closed, Grade Extra Coarse, Grit 36, Overall Diameter 3 in, Quick Change System TR, Series 361F, Maximum Operating Speed 20, 000 RPM, Resistance Properties Heat, Color Brown, Package Quantity 50