Trydel Coolant System & Radiator Stop Leak is a fast-acting cooling system treatment designed to temporarily seal minor leaks and protect engine cooling components. Its advanced formula circulates safely through the system to stop seepage in radiators, hoses, heater cores, and gaskets while helping to prevent corrosion and scale build-up. Formulated not to affect metals in cooling system, it restores cooling system integrity, reduces overheating risk, and helps extend the life of the radiator and engine.