Parker Brass Pipe Fitting, Hex Coupling, 3/8" NPT Female X 1/4" NPT Female Hex coupling for connecting and extending pipes going in the same direction Female National Pipe Taper (NPT) threads on both ends for connecting male pipes Made from brass, for machinability and higher corrosion resistance than steel NPT thread for compatibility with a range of threads More economical than steel Rolled male threads for extra strength