12 brand new 4-1/2" aluminum oxide sanding flap discs Will fit on all 4-1/2" angle grinders that have a 7/8" arbor Maximum speed 13,300 rpm (2) Each 40, 60, 80, 100, 120,180 Grit Flat type #27 Resin fiber w/fiberglass backing plate High density Use for deburring, finishing work surface and light grinding Good for non-ferrous metal, high speed steel, carbon and alloy steel paint and rust removal Reduce warping of thin metal