Flap Disc Abrasive Type Coated Abrasive Material Zirconia Alumina Grade Extra Coarse Backing Plate Material Fiberglass Connector Size 7/8 in Connector Type Unthreaded Hole Density Rating Standard Flap Disc Type Type 27 Overall Diameter 4 1/2 in Series Predator FF Backing Material Polyester Backing Weight Y Coating Coverage Closed Grit 36 Maximum Operating Speed 13 300 RPM Color Green