SMC KQ2H04-M5A Brass Push-to-Connect Tube Fitting, Adapter, 4 mm Tube OD x M5x0.8 Male Connector with sealant for connecting two pipes in a piping system Push-to-connect fitting connects to pipes or tubing on one end and has an NPT male connector on the other Made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability Working pressure of up to 145 psi Operating temperature ranges from -5 to 60 degrees C This product is not intended for use in potable water systems