Flap Disc, Abrasive Type Coated, Abrasive Material Zirconia Alumina, Grade Medium, 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 Ovation, Backing Material Fiberglass, Backing Weight H, Grit 60, Maximum Operating Speed 13,300 RPM