Professional quality discs provide fast, efficient method of grinding, blending, leveling and finishing metal surfaces. Quickly and securely locks into place with just a twist. For use with 2" back-up pad in a die grinder or electric drill. 25,000 max rpm (revolutions per minute). Diameter: 2 In. Grit: 36 Grit Grain: Zirconium Oxide Backing Material: Resin Bonded