Interstate Pneumatics FM44RL 1/4" MPT Special Steel Fitting. This professional contractor / professional grade hose barb is machined from a solid steel stock using CNC machine center. Steel is corrosion resistant and provides a tight seal on the hose. For use with PVC, PU, Rubber hose or tubing and to be secured with a hose clamp or crimped ferrule. Maximum working pressure 300 psi.