Super Radiator Anti-Rust contains an inhibitor package that coats and helps protect key cooling system metals from corrosion. This product can be added to antifreeze/coolants between changes to boost the depleted corrosion protection of these fluids. When used according to package directions, this specially formulated product will not cause over-addition problems such as reduced heat transfer or inhibitor precipitation that can be detrimental to the antifreeze in the system. Prestone Super Radiator Anti- Rust provides rust protection between coolant changes and is compatible with conventional DEX-COOL antifreezes.