The Gas changeover valve is a brass valve purposely designed to work with compressed air and CO2.
The valve is robust and does not leak. It is not prone to breaking or leaking like plastic valves.
It comes with duplex safety valves and is designed to wall mount. You then bring a feed from the compressor to one side of the valve and CO2 feed into the other side. It is easy to changeover the valve from one either Air or CO2 by using the lever to select the correct source.
If CO2 is not being used it should be isolated and the main tank gas valve closed to ensure safe gas use.