Flap Disc Abrasive Type Coated Abrasive Material Ceramic Grade Extra Coarse Backing Plate Material Fiberglass Connector Size 7/8 in Connector Type Unthreaded Hole Flap Disc Type Type 29 Overall Diameter 4 1/2 in Series Apex Backing Material Polyester Backing Weight Y Grit 36 Maximum Operating Speed 13 300 RPM Features Hard Edge