Flap Disc, Abrasive Type Coated, Abrasive Material Zirconia Alumina, Grade Extra Coarse, 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 BlueFire R884P, Backing Material Cotton, Backing Weight Y, Coating Coverage Semi-Open, Grit P36-40, Maximum Operating Speed 15,300 RPM, Color Blue