Flap wheel sanders are made from aluminum oxide grain for sanding, polishing 24 pieces flap sanding wheels includes 6 sizes: 20mm, 25mm, 30mm, 40mm, 50mm, 60mm All of the flap wheels are 1/4'' shank fits rotary tools, drill and pneumatic power tools Perfect for surface polishing, rust removal, weld burr and paint removal and so on Package contents: 24 pieces assorted sizes 1/4-inch shank flap sanding wheels Flap wheel sanders are made from high performance aluminum oxide grain and metal. 1/4 inch shank fits for electirc rotary tools, drill, grinder and pneumatic power tools. Perfect for surface polishing, rust removal, weld burr and paint removal and so on.