Mercer Abrasives 397MRN-10 Aluminum Oxide Surface Prep Wheel, 7-Inch by 7/8-Inch, Maroon, Fine Grade, 10-Pack Non-woven synthetic fiber impregnated with abrasive grain Three different grades Type 27 shape Available with 5/8-Inch -11 threaded hub Maroon: Aluminum Oxide/Fine; Used to clean and polish metals