FW Murphy, 5701073, OPL Series Gage, 4.5" Diameter Dial, 1/4" NPT, Grade A Phosphor Bronze Tube Brass Socket, Panel Mount, 30" Vac - 30 Psi
Pressure gage instrument is combination pressure indicating gage with adjustable low and high limit switches. Limit switches can be wired directly to electric pilot circuits to operate alarms, shutdown or the start/stop of engines and electric motors. It feature a 4-1/2 in. (114 mm) dial for easy viewing. Adjustable limit switches are accessible from the front of the gage instrument. Limit contacts have self-cleaning motion to enhance electrical continuity.
It is a gage with panel mounting. It is typically used in control panels for compressors, pumps, etc. Contact lead termination is by pigtail wires.
For more information, please see 
Data Sheet
