Micro Matic Primary 1 Way CO2 Regulator (60 PSI) 
A primary CO2 regulator from Micro Matic with one gauge going up to 60 PSI.
The inlet is CGA320, and the shut-off valve outlet has a 3/8" OD barb.
It has a safety relief set to 55 to 65 PSI.
The body is brass, and the bonnet is aluminum.