Open Mesh Abrasive Sandcloth is Wm. H. Harvey's best grade for cleaning and preparing copper tubing and fittings for soldering. It is fully waterproof; 180 grit gives smooth finish. Open mesh combines open nylon fabric with phenolic resin adhesive and aluminum oxide to give a sharp cutting plumber’s roll. If cloth becomes loaded with metal filings, simply rinse in water or tap on hard surface. Can be used on both sides...lasts twice as long.