Package Contents: 30 pieces Circular Sanding Disc (225mm 80 grit, 6 holes). High Quality: Sanding disc is equipped with a thick D-class paper base, made of high quality alumina with abrasion resistant sand, high strength resin bond system increases the service life. Easy to Change: Durable reverse sticker makes changing sanding disc easier and more convenient; Hook and loop backing for faster mounting. For Size: 225 mm/9 inch diameter, with 6 pre-drilled holes for dust extraction, suitable for Random Orbit Sanders/Sanding/Polishing/Rust Removal. Multipurpose Sanding Discs: Suitable for grinding and polishing wood, jewelry, glass, stone, car, machinery, metal, non-metal, rubber, leather, plastic, etc.