1.CE,ISO9001-2008,ROHS 2.Diaphragm seal structure 3.Easy maintenance 4.Good waterproof performance 5.Normal Closed This guiding type valve adopts the diaphragm seal structure,with zero differential pressure starting function,large flow,simple structure,easy maintenance,good waterproof performance and multiple wiring direction. TW Series 2 way brass Solenoid Valve