John Guest 1/2'' X 3/8'' X 3/8'' Polypropylene Angle Stop Adapter Valve The Pp Range Of Inch-Size Push-In Fittings Is Offered For Tube Sizes 1/4" O.D. To 1/2" O.D. The Fittings Are Manufactured In White Polypropylene With Food Grade Epdm O-Rings.