The original Permatex Blue. Will not foul oxygen sensors. Replaces almost any cut gasket. Makes reliable �formed-in-place� gaskets that resist cracking, shrinking and migrating. Coats pre-cut gaskets to increase reliability. Temperature range -65�F to 500�F (-54�C to 260�C) intermittent; resists auto and shop fluids. First generation 1970-1980 gasket maker.