Loctite® RTV 5920™ Copper RTV Silicone has the highest temperature rating of any Loctite RTV (up to 700° F), which makes it ideal for sealing exhaust header flanges. Low odor, non-corrosive formula seals gaps up to 0.25" (6mm). If you have ever lost a header gasket, apply a bead of 5920 to each side of the gasket before installation. The adhesive RTV will significantly reduce the chances of blowout, even if the header flange is mildly warped. In fact, if the flange is straight, many racers prefer to use 5920 to eliminate the gasket completely. 2.37 oz (70 ml) tube, includes one nozzle.