Polytrol is a deep penetrating oil which restores the original colour and appearance of dull or tarnished painted surfaces, plastics, gelcoats, metals, and other surfaces. It penetrates the surface, re-wetting the pigments to restore their lustre and colour which has been lost through exposure to sunlight, rain, and pollution and it also gives corrosion protection. When used on tarnished metals, it brings back the shine and gives long-term protection against corrosion. On polished brass, it also retards tarnishing to give longer intervals between polishing. Please see the directions for use to find out how to apply it.