Fiber Disc Backup Pad Abrasive Mount Type Threaded Hole Abrasive Mounting Quick Change System Not Applicable Connector Size 5/8 In.-11 Connector Type Threaded Hole Backup Pad Shape Round Device Material Rubber Density Medium Maximum Operating Speed 11 000 RPM Number of Vacuum Holes Non-Vacuum Color Black Overall Length Not Applicable Overall Width 4 1/2 in Overall Diameter 4 1/2 in Overall Thickness Not Applicable Product Type Disc Backup Pad Features Ribbed