Match and Finish Flap Brush, Abrasive Material Aluminum Oxide, Abrasive Type Non-Woven, Backing Material Not Applicable, Backing Weight Not Applicable, Connector Size 5/8 In.-11, Connector Type Threaded Hole, Grit 36, Series CF-MF, Flap Width 4 in, Maximum Operating Speed 3,500 RPM, Overall Diameter 4 1/2 in, Grade Extra Coarse