4” x 4” x 3/4” quad key shaft Interleaf Wheel Abrasive Drums by BHA - Black Hawk Abrasives are designed to sand and condition simultaneously making it great for removing moderate rust, paint, or body filler while also prepping for next stage finishing. Each 4 inch interleaf wire drawing wheel is manufactured with impregnated non-woven pieces and coated aluminum oxide sanding flaps in an alternating fan-like design centered around the 3/4” keyed shaft. The aluminum oxide flaps allow you to strip and remove material but not too much. The porous, non woven structure promotes airflow and resists loading which prolongs the useful life of the wheel and reduces heat buildup which may stain or distort work pieces. The 4” interleaf flap drum by BHA is able to clean, blend and finish while keeping the work piece intact and offers a greater sanding surface area compared interleaf flap discs for angle grinders. With it's alternating sanding flaps and surface conditioning material, the 4 inch black hawk abrasives interleaf flap wheel drum is uniquely suited for blending scratch patterns or parting lines, cleaning welds, oxidation removal, de-scaling heat treated aluminum, removing rust, and creating a satin finish polish on certain metals. This drum is affixed with a hub that fits 3/4 inch keyed shaft that attaches to surface finishing machines and linear grinding machines (A.K.A. Burnishers, burnishing machines, contouring grinders, etc.) and is available in 80 grit, 120 grit, and 240 grit.