Camax are now stocking the Wago meter Termination Rails separate to the Unit; which are pre-wired 3-Phase 4 wire and are suitable for a variety of different meters (Popular choices being Elster A1700 or Elster A1140).
The wiring is designed for MMU's
Voltage input: 415Volts
Wago LV meter rail MMS (Meter Managment System)