Mill-Rose original aluminum oxide mesh for copper tube cleaning. A fully waterproof product made with open nylon fabric, phenolic resin adhesive, which makes it waterproof, and rugged aluminum oxide. Coated on both sides of the nylon fabric to produce a long-lasting sharp cutting product. If this material becomes coated (loaded) with copper, brass or other non-ferrous or plastic residue, simply rinse in water or tap against a hard surface to clean.