Bar's Leaks 1196 Radiator Stop Leak 2X Concentrate Sealer 5.5 Oz is an effective cooling system sealant, specially formulated to stop system leaks and drips caused by normal wear and age. Its convenient 11 oz bottle helps to easily pour it into radiator tanks. With a concentration 2X higher than other sealers, it helps to quickly and reliably patch leaks, enhancing engine performance and extending the life of your cooling system.