Prestone Radiator Flush and Cleaner is a 2-in-1 formula designed for light flushing and heavy-duty cleaning for cooling systems to help prevent overheating, the #1 cause of engine failure. This premium formulation is designed to remove heavy rust and scale deposits in neglected cooling systems. These deposits can dramatically restrict coolant flow and reduce heat transfer, which may lead to possible overheating, breakdown, or costly repair. A super-chelating additive effectively removes heavy deposits by drawing metal oxides into the solution. Though strong enough to help restore maximum cooling system efficiency, this non-toxic, non-acidic product is easy-to-use and safe for all cooling system metals.