Package Content: 30pcs Circular Sanding Disc(120# 240grit, 15 Discs per Grit Size). High Quality: Sanding disc is equipped with thick D-class paper base, made of high quality alumina with abrasion resistant sand, high strength resin bonding system increases the service life. Easy to Change: Durable reverse velcro makes changing sanding discs easier and more convenient; Hook and loop backing for faster mounting. For Size: 225mm/9 inch in diameter, with 8 pre-drilled holes for dust extraction, suitable for Random Orbital Sanders/Sanding/Polishing/Rust Removal. Multipurpose Sanding Discs: Suitable for grinding polishing wood, jewelry, glass, stone, car, machinery, metal, non-metal, rubber, leather, plastic etc.