Hylomar Gasket Sealant is a non-hardening, non-migrating, anaerobic sealant designed for use on gaskets and flanges. It is a polyester urethane-based sealant that forms an elastic seal that remains flexible and will not harden, shrink or crack. It is resistant to oil, gasoline, coolants, water, and antifreeze and will not become brittle with age. It is also resistant to temperatures up to 500 Degree F and is non-corrosive. It is used to seal the gasket and prevent leakage, and is ideal for sealing oil pans, differential covers, and other flanged assemblies.