Hi-Lo UK DKD coupling 3/8 is worldwide compatible, designed for tapping points and pressure regulators. 
 
The quick-action coupling DKD according to EN561, ISO 7289:
Safe interruption of gas flow by automatic gas cut-off when disconnecting
No mixing up by different coding of coupling pins
Prevents accidental disconnection
All metal components in brass 2.0401 / spring 1.4310
 
Safety elements of the Hi-Lo UK quick-action coupling DKD:
SV Shut-off valve
 
Function:
Push-Systems 

Coupling:
Hold the sleeve and connect it with the coupling pin by pressing both parts together until they are locked.
 
Uncoupling:
Push the sleeve forward and remove the coupling pin from the coupling body.
 
Maintenance:
Couplings are wearing parts and have to be tested by a qualified and authorised person (at least once a year). The tests have to be performed when the couplings are connected as well as disconnected.
Leakage tests are to be performed with inert gas or air (free from oil and grease) or the operating gas.
It is not allowed to open the quick-action couplings.