Flap Wheel, Abrasive Material Aluminum Oxide, Abrasive Type Coated, Backing Material Cotton, Backing Weight Y, Grit P40, Series R369, Flap Width 1 in, Maximum Operating Speed 25,000 RPM, Shank Size 1/4 In.-20, Overall Diameter 1 5/8 in, Grade Coarse, Shank Type Threaded, Coating Coverage Closed, Resistance Properties Wear