Our Fuel Tank Safety Vents with Pressure and Thermal Relief are designed to provide patented anti-spill protection and meet all applicable DOT requirements. These vents feature valves with pressure and thermal relief features, making them ideal for diesel applications. With a 1/4" - 18 PTF size, they are sold individually and fit most pre-1992 Kenworth makes and models. Ensure the safety and reliability of your fuel tank with these practical and essential vents.