The 3M 3" x 21" 50 Grit Coated Aluminum Oxide Coarse Abrasive Belt features aluminum oxide abrasive with a 50 grit coarse grade for sanding and surface preparation applications. The tube-shaped belt is compatible with equipment for use on inner and outer surfaces. Its X-weight cloth backing provides strength and flexibility. The resin bond and aluminum oxide abrasive are suitable for dry sanding operations. This belt is intended for use with a rubber expander wheel attachment, sold separately, on die grinders or rotary drills.