Colder PLC42004 Acetal Tube Fitting, Insert, Straight Thru, Panel Mount, 1/4" Insert x 1/4"Barb Insert coupler has one or more ribs for creating a tight seal and connects tubing in a straight run Insert coupler on one end and barbed construction on the other end for connecting tubes with different ends on a bulkhead Acetal copolymer plastic for low moisture absorption and high tensile and flexural strength Working pressure of up to 120 psi Operating temperature range from -40 to 180 degrees F