Permatex PermaShield Fuel Resistant Gasket Dressing & Flange Sealant is specially formulated for superior fluid resistance. This polyester urethane based gasketing compound withstands extreme temperature changes without hardening. Its non-setting, non-hardening character remains tacky even with rapid changes in temperature, enabling repeated assembly and disassembly of parts. Suitable as either a gasket maker or dressing, PermaShield seals surface imperfections between metal parts and is ideal in high performance applications.