Use AGS plugs for terminating or plugging a port opening. Tighten with a wrench for a leak-proof seal. Recommended uses include copper, brass, aluminum, and steel hydraulic tubing. Working temperatures: -65 degrees F to 250 degrees F. Applications include brake, fuel, transmission. AGS brass and steel fittings are comprised of Tube Nuts, Unions (Couplers), Adapters, Elbows, Tees, Bushings, Connectors, Grease, etc... AGS fittings are held to the strictest standards to perform flawlessly in their intended applications. Fittings are offered in a variety of packaging options, including: retail clam-shells, bulk boxed, and plastic tray assortments.