Hobbs HR MTR Pres Swch M4006-4

Normally open. Closes at 4 PSI. Single circuit with two insulated terminals. Switch has silver contacts enclosed in weatherproof case. 1/8" male pipe thread connection.

If using on a water application (Rotax for instance) use
P/N 10-00326 Honeywell Hobbs Hour Meter

Pressure Switch 76575-4

Dimensions: 2.5X2.5X2.5