Fast, odor-free rust and hard water stain remover, no solvents,and biodegradable. Removes rust stainsfrom fiberglass, fiberglass boat hull, stainless steel, fabrics, clothing, concrete, wood, copper, vechicles, brake dust, leaf stain, carpets, bathtub, stink, chrome and painted surfaces. will also clean ceramic grout. Removes grease and organic stains from conrete (srub with brush). Not for use on glass, windows, or mirrors.