The 320 Series Coupling is an easy to use, heavy duty, long lasting coupling, it is a one hand operated safety coupling that relieves pressure before disconnecting, eliminating the risk of hose kickback, the male threads on the coupling and nipple are provided with a thread seal at the factory, the couplings have smaller external dimensions than comparable designs and are also available as an aluminum design, the fully automatic process simplifies operation, the eSafe design complies with ISO standard 4414 and EN 983