Work Sharp s Original Knife and Tool Sharpener is powered by premium abrasives, engineered specifically for every stage of sharpening with the Knife and Tool Sharpener from complete restoration to applying a mirror finish on your edges. Extra-Coarse Abrasive Belts are intended for restoring damaged edges or reprofiling applications. Their special Norton ceramic alumina formulation allows for quick, safe shaping of edges. These are an exact replacement for the Extra-Coarse grit included with the Knife and Tool Sharpener belt assortment.