Metal Guard 450 is a low odor, non-staining, water-displacing rust preventive with excellent penetrating properties. That is applied to aluminum, steel, Stainless Steel, or copper alloy substrates by spray, immersion, brushing, or flood coating. Metal Guard 450 meets Mil-C-16173 Grade 3 Specifications. Metal Guard 450 is also used for protection against rust and corrosion on automobile parts and accessories, sewing machines, firearms, fasteners of all types, small gasoline engines, machine tools, dies, jigs, fixtures, and metal stampings.