 K-Seal fights the most difficult cooling system leaks, including head gaskets and engine blocks. Now there's K-Seal Ultimate featuring 33% more sealing power than original K-Seal. K-Seal's unique formula works with all water-cooled engine castings, including aluminum. No need to drain or flush your cooling system. Just shake the bottle and pour K-Seal Ultimate into the cooling system and you're back on the road. K-Seal Ultimate is now available at Walmart. Learn more at K-Seal.com. Don't just seal it.