These tube fittings are commonly used to connect pipes as air, water, fuel, oil, and gases in a quick and simple way. Work with copper, brass, aluminum tubing.||Male Thread Size: 3/8PT(Approx OD 16.3mm); Fit Tube OD: 6mm / 1/4"||Brass material features corrosion resistance, high strength, high hardness, strong chemical resistance, high strength at low temperature.||Put the nut on the copper pipe, use a flare tool to flare the copper pipe, and then use a wrench to install the elbow fitting.||Flaring tool is required for installation. Please confirm the correct size before ordering.