SPOC 1/4-03 is a model number of 1/4" O.D tubing x R 3/8 male thread hex socket head male connector stainless steel push in air fittings. Its round shaped body and internal hexagon allows it to be installed anywhere space is limited. Connect 1/4" pneumatic tubing and installed to R, PT, BSPT 3/8 female thread. 1/4" x R 1/4 stainless steel round male straight push to connect air fittings can hold nylon tubing, PU tubing, PE tubing, Teflon tubing and can transfer air, water, oil and weak corrosive fluid.