Product Details:
Range: 20-300 psi
Action on pressure rise: Breaks only
Switch type: SPST
Reset: Manual

Honeywell L404C1139 pressuretrol: 
Can be used with steam, air, non-combustible gases, or fluids non-corrosive to the pressure sensing element.
Stainless steel diaphragm (except 300 psi [21.1 kg/cm2; 2068 kPa] models) also allows use with ammonia, oxygen, distilled water and similar media.
L404B is recommended for supervision of atomizing medium pressure in oil burner systems.
Models are available with single-pole, single-throw (spst), single-pole, double-throw (spdt), or double-pole single-throw (dpst) switching and in a variety of operating ranges.
Dustproof, trouble-free mercury switches (all modelsexcept L404F, which has snap-acting switch).
Automatic reset models have adjustable, subtractive differential.
Trip-free mechanism on manual reset models assures that limit function of controller cannot be defeated by jamming reset lever.
Screw adjustments made on top of case.
Scaleplates marked in English (psi) and Metric (kg/cm2) units.
L404F models available with European enclosure, British Standard Pipe Threads, ground screw, and scale plates marked in kg/cm2 and either psi or kPa.
Clear plastic cover on case to observe pressure settings and switch action.
Leveling indicator visible through cover.
Hexagonal fitting with 1/4-18 NPT internal threads for direct mounting to 14026 Steam Trap (siphon loop).
Surface mount is available using screws through holes (knockouts) in case backing.