standard:ISO-9001 2000 reliable quality ,resonalbe price. Four Circuit Protection Valve Original NO. : AE4170 ports:port1m22*1.5,port21,22, ... open press :21,22,23,24:7.0 comment:feed back all circuits 1.OEM products, abide strictly by the ISO9001 ... WISH! WE WISH TO BE YOUR TRUSTWORTHY SUPPLIER! Four Circuit Protection Valve (AE4170)