Flap Disc Abrasive Type Coated Abrasive Material Zirconia Alumina Grade Coarse Backing Plate Material Fiberglass Connector Size 5/8 In.-11 Connector Type Threaded Hole Density Rating High Flap Disc Type Radial Overall Diameter 7 in Series Z SGP CURVE Backing Material Fiber Backing Weight X Grit 40 Maximum Operating Speed 8 500 RPM