Flap Disc, Abrasive Type Coated, Abrasive Material Zirconia Alumina, Grade Medium, Backing Plate Material Fiberglass, Connector Size 5/8 in, Connector Type Unthreaded Hole, Density Rating Standard, Flap Disc Type Type 29, Overall Diameter 4 in, Series XC1176, Backing Material Fiberglass, Backing Weight X, Grit 60, Maximum Operating Speed 15,300 RPM