The unit is made of two chemically nickel-plated brass castings, one casting for the regulators bodies, and the other casting for the zone shut-off valve; the regulator body has two decompression lines with two EURO/A regulators connected in by-pass through four ball valves, two on the inlet and two on the outlet of the same. A pressure gauge measures the system pressure upstream of the regulator; the area valve on the regulator body outlet has a ball valve on the inlet to shut off the gas and there is a fitting for a proximity sensor that reads the open/closed status of the valve, an emergency socket and a pressure gauge with electrical contacts. All the valve seats and pressure gauges are fitted with check valves to prevent gas leaks when servicing.The inlet and outlet connections are made using a Ø16 mm weld-on pipe. The unit also has a block for physical disconnection.If the 2nd stage unit with built-in area valve is installed outside the ward in the filter room, it can act as a shut-off module and therefore satisfy the threefold function of a fire shut-off valve, regulator module and zone shut-off valve, meaning notable time savings when installing and less building work.