Permatex Super 300 Form-A-Gasket Sealant is a non-hardening sealant designed to resist heat transfer fluids such as oil or antifreeze. Temperature range -65 degree fahrenheit to 400 degree fahrenheit, resists antifreeze, aviation fuels, high-detergent oils and lubricants. When a chemical gasket is not an option, Permatex offers a wide range of gasket sealants suitable for applications on both import and domestic vehicles of any model year or performance caliber.