Permatex . Sensor-safe blue RTV. The original 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 deg. F. to 500 deg. F. intermittent; resists auto and shop fluids. Suggested applications : Valve covers, oil pans, timing covers, water pumps, thermostat housings, transmission pans. 3 oz. tube. Carded.