Granville Rust Converter is the rust convertor used by the oil & marine industries, the Mo D & NATO. It is used to stop corrosion in environments far more severe than your car will ever see... & it WORKS. Drying to a tough gloss black finish it can then be top coated with most paints. Environmentally & ecologically safe. Acid & lead free. Non-flammable. MUST be applied to rusted ferrous metals. Kills old rust & stops new forming. 3 Sizes Available: 250ml, 1 litre, 5 litres. Still unsure? Read our customer review here.