GP12638 Hook and Loop Rotary Backing Pad with 5/8''-11 Thread, Sanding, Polishing Backer/Diameter 6 inch Diameter: 6 inch Thread Size: 5/8''-11 25mm EVA rigid layer makes this pad excellent for high speed sanding and polishing flat surfaces Hook and Loop Fastener (Velcro Type) Max Speed: 12200 RPM