Nyalox 3 inch 5/8-11 Gray Coarse Angle Grinder Cup Brush with aluminum oxide abrasive impregnated throughout each nylon bristle. 5/8-11 female thread spins directly onto your angle grinder. Abrasive grain is in each and every nylon bristle. Use like a wire brush on wood, metal, tile, etc. Works like a power sander and removes old finishes.