GP12611 Hook and Loop Rotary Backing Pad with 5/8''-11 Thread, Sanding, Polishing Backer/Diameter 5 inch Diameter: 5 icnh 20mm PU semi-flexi layer makes this pad excellent for polishing or sanding curved and flat surfaces Thread Size: 5/8''-11 Hook and Loop Fastener (Velcro Type) Max RPM: 6500