K2 RADIATOR STOP LEAK is the highest quality product for sealing radiators. Seals even large leaks quickly and effectively. Ideal for removing leaks caused by stone impacts, vibrations or other mechanical damage. Can be used in all types of radiators. It is miscible with all types of coolant. including the latest long-life coolants. It does not impede the circulation of the fluid within the system. Safe for the heater and other components of the cooling system.