Ultra Copper High Temperature Gasket Maker - 80 mL Permatex For high operating temperatures, turbocharger applications and exhaust systems. The most advanced, high temp RTV silicone gasket maker available. Sensor-safe, low odor and non-corrosive. Three times more oil resistant than conventional silicones; eight times more flexible than cut gaskets. Temperature range -65°F to 700°F intermittent; resists auto and shop fluids and vibration.