Flap Disc Abrasive Type Coated Abrasive Material Zirconia Alumina Grade Coarse Backing Plate Material Phenolic Connector Size 7/8 in Connector Type Unthreaded Hole Density Rating High Flap Disc Type Type 27 Overall Diameter 4 1/2 in Series Tiger Big Cat HD Backing Material Phenolic Grit 40 Maximum Operating Speed 12 000 RPM Color Blue