Raypak Pressure Switch aka Flow switch. Suits all Raypak Heaters. Barksdale - The Little General Pressure / Flow Sensor Switch.
Found on many older Raypak gas heaters, such as RP2100 and others.
.5 - 5.0 PSI adjustable
3A 125/250 VAC
No Longer Available - Replace with this one. (Same Thread, etc)