Flap Disc Abrasive Type Coated Abrasive Material Ceramic Grade Coarse Backing Plate Material Plastic Connector Size 5/8 In.-11 Connector Type Unthreaded Hole Density Rating High Flap Disc Type Type 27 Overall Diameter 4 1/2 in Series Elite Backing Material Cloth Backing Weight XP Coating Coverage Closed Grit 40 Maximum Operating Speed 13 300 RPM