H7374 Flap Disc Abrasive Type Coated Abrasive Material Zirconia Alumina Grade Medium Backing Plate Material Aluminum Connector Size 5/8 In.-11 Connector Type Threaded Hole Density Rating Standard Flap Disc Type Type 29 Overall Diameter 4 1/2 in Quick Change System Not Applicable Series Tiger Aluminum Back Backing Material Aluminum Grit 80 Maximum Operating Speed 13 000 RPM