Dixon SV20 Steel Air Hose Fitting, In-Line Swivel, 1/2" NPT Male x 1/2" NPT Female, 250 psi Pressure Swivel adapter for connecting hose or fittings of different types Connects to a female NPT threaded connection on one end and a male NPT threaded connection on the other Steel for better weldability and increased rust resistance to wrought iron Operating pressure of 35 to 250 psi at 70 degrees F For air service only