These wheels and cylinders provide a smooth, scratch-free satin finish. No other rubberized abrasive can accomplish this in one step. The 442-637 and 442-647 wheels are a little harder than the others listed, but provide the same finish. All wheels are 1/8" thick. Cylinders have a hole in one end for threading onto tapered mandrels. 1/16" hole diameter. White colored abrasives are slightly harder, but provide the same finish as gray. Sold in packages of 20.