FW Murphy, 5700813, OPL Series Gage, 4.5" Diameter Dial, 1/2" NPT, 316 Stainless Steel Tube and Socket, Surface Mount, with Low Limit Lockout Switch, Enclosed with Explosion-Proof Case; Class I, Div.1, Groups C & D, 0-2000 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.
Is a surface mount, indicating pressure gage and switch. Adjustable high and low limit, ungrounded contacts are used to operate alarm, shutdown or start-stop circuits. Pointer closure against either of the adjustable contacts completes the pilot-duty circuit. An SPST toggle switch is provided to override the low limit contact for equipment startup. Suitable for engines or electric motors with appropriate magnetic switch or transformer relay assembly.
For more information, please see 
Data Sheet
