Silverhook Stop Leak for Radiators quickly finds and permanently seals radiator leaks. It is formulated to inhibit the formation of rust and corrosion to help prevent further leaks. It is made from a blend of surfactants, corrosion inhibitors and sealants. Stop Leak for Radiators may be used with antifreeze and is harmless to rubber hoses, gaskets and gasket cements. It is suitable for petrol and diesel engines. Size: 325ml