Up for sale I have two like gauges that do work.

1st the bigger more colorful one has a 3 inch diameter face.  It is for measuring water temp off of a mixing valve or an eyewash station.

It was removed from a guardian equipment eyewash station from a local medical facility.

The smaller one is U.S. made by Marsh, it is vintage and was a spare part for a Hospital pneumatic system, where you measure compressed air PSI.

Face diameter is 1 3/4 in.

It works and is basically new old stock.  The pneumatic system has been replaced.

These will ship well packaged from a smoke & virus free home.

The pneumatic has 1/4 inch nipple that is threaded.  I do not know the tread size for the bigger gauge.