Colder PLCD22006 Acetal Tube Fitting, Insert, Shutoff, In-Line, 1/4" Insert x 3/8"Barb Insert coupler for connecting two pipes in a straight run Coupler on one end and barbed construction on the other end for connecting two pipes or tubes with different ends Made of acetal copolymer plastic for low moisture absorption and high tensile and flexural strength Working pressure of up to 120 psi Operating temperature ranges from -40 to 180 degrees F