Flap Disc Abrasive Type Coated Abrasive Material Zirconia Alumina Grade Coarse Backing Plate Material Fiberglass Connector Size 7/8 in Connector Type Unthreaded Hole Density Rating High Flap Disc Type Type 27 Overall Diameter 4 1/2 in Series BlueFire R860 Backing Material Cotton Backing Weight X Coating Coverage Semi-Open Grit P60 Maximum Operating Speed 13 300 RPM Color Blue