Flap Disc Abrasive Type Coated Abrasive Material Zirconia Alumina Grade Coarse Backing Plate Material Aluminum Connector Size 5/8 in-11 Connector Type Threaded Hole Density Rating Standard Flap Disc Type Type 29 Overall Diameter 4 1/2 in Series Tiger Aluminum Back Backing Material Aluminum Grit 40 Maximum Operating Speed 13 000 RPM Color Blue