Quick coupling. Just click together with the original vehicle connections. Handy if you want to upgrade your fuel system without changing any lines routed over the fuel tank. Also used for sensors.   SPD AN fittings have the absolute highest quality available. All AN fittings are hard anodized, making them highly wear resistant. The AN fittings can be used with all fuels avalible like gasoline, methanol, ethanol and diesel. They are also suitable for use in water, air and oil systems. We offer a full 5-year warranty on all SPD AN connections.