Series 4000 Pressure Switch
Product Specifications:

Switch Type: Pressure
PSI Rating: 1 to 11 psi
Manufacturer: Tridelta/Tecmark
Plumbing Connection Size: 1/8"
Plumbing Connection Type: Male National Pipe Thread (mnpt)
Pressure Switch Amperage: 21A
Pole/Throw: Single Pole Single Throw (spst)