●Size: Female AN6 to Male AN4, the thread size of 6an is 9/16-18 UNF, the thread size of 4an is 7/16-20 UNF. ●Parameter: Max working pressure: 1500PSI.Temperature range: -65°F-252°F. ●Material: Made of aluminum alloy 6061-T6, anodized black surface. ●Sealing: The AN side is sealed by a 37 degree angle. ●Application: Widely used in fuel system, cooling system, LS swap etc.