GP12642 Hook and Loop Rotary Backing Pad with 5/8''-11 Thread, Sanding, Polishing Backer / Diameter 5 inch Diameter: 5 inch Thread Size: 5/8''-11 20mm PU semi-flexi layer makes this pad excellent for sanding and polishing curved or flat surfaces Hook and Loop Fastener (Velcro Type) Max Speed: 6500 RPM