- 40-pack includes 8 sizes: 16 mm, 20 mm, 25 mm, 30 mm, 40 mm, 50 mm, 60 mm, and 80 mm. - Common shank size and grit: 1/4 inch shank; 80 grit abrasive flap wheels. - Quality materials: flap wheels made from high performance aluminum oxide grain on metal with quality abrasive coating. - Uses and performance: suitable for paint removal, stain removal, and floor polishing; also effective for deburring and polishing. - Compatibility: designed for use with die grinders, cordless drills, straight grinders, and sanding wheels for electric drills. - Why you need them: versatile size range covers tight corners and large surfaces, enabling efficient material removal and finishing in a single set. - Use scenarios: 1) Stripping old paint and finishing details on furniture in tight curves and corners. 2) Removing rust and smoothing metal surfaces on automotive or garage equipment. 3) Preparing and polishing small floor areas or stair treads for re-finishing.