Harris Pressure Regulator Valve w Gauges 4000 PSI.  I could not find a model number on this but one of the gauges says 4000 PSI, and the other says 500.  Please take a look at the photos for other specs and possible usage. 

I purchased this from a government facility.

Tag: C-T4513

Bin: 19H-NACLE

Shelf: 3.8