This is a pressure sensor used on the Dr. Oligo high throughput synthesizers to monitor the primary bottle pressure which is the pressure going into the bottle pressure regulators. It is also used to monitor the purge / drain gas pressure on the Dr. Oligo high throughput synthesizers. A 0- 15 PSI switch is used to monitor the pressure that is coming out of the Bottle Pressure Regulators and going to the Bottles. The PN for that pressure switch is 502-101111.