Nyalox abrasive impregnated brushes are safer than wire brushes for paint and rust removal on wood, metal, tile or masonry. Nylon bristles don't break, shed, rust or prick your hands. Three Color Coded Abrasive Grits:gray is coarse, orangeis medium, and blue is fine. Up to ten times the life of a wire brush! NEW White non abrasive brush for general power driven cleaning!