*Has CE, ISO9001,UL certificate *long service life, good quality *up to 500million more cycles *free maintaince eaternal pilot witch can prolong the service life, no leak for 500 million times,has adjustive airproof cover between relif orifice and slide block.Control air source : neutral gas, air. Ordering Code: ZF — 15 B | | |Series Pipe Size Type of Gateway 15: G1/2 B: Normal Closed 20: G3/4 T: ...