Flap Disc Abrasive Type Coated Abrasive Material Aluminum Oxide 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 4 1/2 in Series A SGP CURVE Backing Material Fiber Backing Weight X Grit 40 Maximum Operating Speed 13 300 RPM Features Performance Coated