Permatex Ultra Blue Multipurpose RTV Silicone Gasket Maker is an excellent all-purpose gasket maker that is suitable across a wide range of applications. Sensor-safe low odor and non-corrosive. Permatex Ultra Blue has outstanding oil resistance and joint movement tolerance. It is eight times more flexible than cork/composite gaskets and three times more oil resistant than conventional silicones. Temperature Range: -65°F to 500°F (-54°C to 260°C) intermittent.