Pneuflex's SPU 1/4 is 1/4 inch O.D tube union straight push in fitting, entirely constructed of 316 stainless steel which can withstand to harsh, corrosive environment. 1/4 inch O.D tube stainless steel union straight pneumatic fitting is used to connect two 1/4 inch O.D tubes made of PU, PA, PE, teflon material.