Flap Disc Abrasive Type Coated/Non-Woven Abrasive Material Ceramic Grade Fine Backing Plate Material Cloth Connector Size 5/8 In.-11 Connector Type Threaded Hole Density Rating Standard Flap Disc Type Type 27 Overall Diameter 4 1/2 in Series ENDURO-FLEX 2-in-1 Backing Material Cloth Grit 150 Maximum Operating Speed 13 300 RPM