E.MC pneumatics&hydraulics supplies varial type brass pneumatic couplers, including milton tpe couplers and plugs, Tru-flate couplers and plugs, ARO type couplers and plugs, Universal type couplers and plugs, ORION types couplers and plugs, etc.Every type has the femal thread couplers and plugs, male thread couplers and plugs, tubing couplers and plugs, and they're exchangable to each other, so that one series can meet many different connection needs.The milton type couplers and plugs, Tru-flate couplers and plugs, ARO type couplers and plugs, Universal type couplers and plugs are most popular in USA, and ORION type couplers and plugs are popular in Europe.