Nulon Extreme Cooling System Flush and Degreaser is a 3 in 1 alkaline cleaning solution for heavily contaminated radiators and cooling systems. Ideal for use where there has been head gasket failure causing oil and fuel to contaminate the cooling system, the 3 in 1 formulation strips oil, grease and scale contaminants from the inside of hoses and metal surface areas to be flushed away. Safe for use in all vehicle cooling systems. Does not harm metal surfaces, gaskets, hoses or plastic parts.