This reducer adapter pipe fitting is made of brass and has a 1/4" male National Pipe Taper (NPT) threaded connection and a 3/8" female NPT threaded connection. This adapter fitting connects pipes or fittings with different end types, diameters, or materials. It has male NPT threads on one end and female NPT threads on the other for connecting to a female and a male threaded pipe or fitting. The NPT threads create a tighter seal than straight threads. This fitting is made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability. <br><p>Brass can be connected to copper, brass, plastic, aluminum, and welded steel. The operating temperatures for this fitting range from -53 to 121 degrees C (-65 to 250 degrees F). <br><p>Note:NPT cannot be accurately calvulated with a linear measuring tool like a Tape Measure, Ruler or Caliper. NPT Thread size is NOT determined by its outside thread diameter in inches.