CRL TPC Surface Protector seals pores in glass, porcelain, ceramic, plastics, polished metals, fiberglass, and marble to make the surface a water, soil, and stain retardant. The clear coating guards against the adhesion and build-up of dirt, grime, mold, mildew, rust and mineral deposits. CRL TPC Surface Protector is excellent for preventive maintenance which will reduce costly cleaning, repairs and replacement when used regularly. Simply spray this glass protector on and polish it off. One ounce of TPC Surface Protection formula protects approximately 15 square feet of glass.