Rislone says its Heavy Duty Radiator Stop Leak with Water Pump Lube features the original Rhizex Pelletized Formula used in hundreds of millions of vehicles worldwide since 1947. It addresses leaks in radiator, freeze plugs, gaskets, and heater cores. In addition, it protects the entire cooling system, inhibits rust and corrosion, lubricates water pump seals, and helps control electrolysis. According to Rislone, the Rhizex pellets dissolve in minutes to solve most common cooling system problems, including internal, external and coolant-to-oil leaks in radiators, freeze plugs, gaskets, and heater cores.