Flap Disc, Abrasive Type Coated, Abrasive Material Zirconia Alumina, Grade Coarse, Backing Plate Material Fiberglass, Connector Size 5/8 in, Connector Type Unthreaded Hole, Density Rating Standard, Flap Disc Type Type 27, Overall Diameter 4 in, Series XC1176, Backing Material Cloth, Backing Weight X, Grit 40, Maximum Operating Speed 15,300 RPM