Designed for sanding and grinding irregular shapes contours and hard- to-reach areas. These premium double resin bonded aluminum oxide sanding drums are ideal for use on wood metal fiberglass and painted surfaces. Brand Name: Gator Diameter: 0.5 in. Length: 3/4 in. Material: Aluminum Oxide Product Type: Abrasive Sleeve Refill Grit: 80 Grit Grade: Medium Number in Package: 3 pc Usage: For use with electric drills Maximum Speed: 4000 rpm Shank Diameter: 1/4 in.