Formulated extra strong to get the job done.Simply spray or wipe on. Removes scum, waterline and rust stains from fiberglass, metal and painted surfaceswithout rubbing. Avoid contact with galvanized metal.Key featuresEasily removes scum, waterline and rust stainsFor use on fiberglass, metal and painted surfacesDoes not contain harmful acids, safe and easy to useNo rubbing or scrubbing