Flap Disc, Abrasive Type Coated, Abrasive Material Zirconia Alumina, Grade Extra Coarse, Backing Plate Material Phenolic, Connector Size 5/8 In.-11, Connector Type Threaded Hole, Density Rating High, Flap Disc Type Type 27, Overall Diameter 4 1/2 in, Quick Change System Not Applicable, Series Tiger Paw HD, Backing Material Phenolic, Grit 36, Maximum Operating Speed 12,000 RPM