The 4WD Extreme Heavy Duty System offers the ultimate in protection. Specifically designed to protect Four Wheel Drive vehicles used by Surf Life Saving Clubs and Professional Fisherman, it will dramatically reduce corrosion on Four Wheel Drive vehicles which are exposed to *CONSTANT use within highly corrosive environments such as; driving on salted roads or beaches. This system may also benefit older 4WD vehicles that are suffering from minor existing rust problems. But remember, as good as this product is, it is not a miracle cure for badly rusted vehicles, as the more rust a vehicle has, the harder it is to stop. (*Daily use)