1Anti Leakage: The hex nut is equipped with a an O ring to avoid leakage, ensuring reduced flow obstruction, space saving, easy and convenient to use. 2Premium Material: The hex head nut is made of premium aluminum material, with hard black anodized coating, rust resistance and oxidation resistance, making fuel block fittings more durable. 38AN Thread: The thread is 8AN, the inner thread diameter is 1/8in Npt, suitable for most fluid, can be used for vehicle repairing and tube work. 4Easy to Install: The Aluminum hex head nut has a simple installation, convenient and time saving, don't need too much tools or complicated steps. 5Small and Compact: The small and compact nut body does not take up too much use space, having exquisite craft, convenient for storage and use.