Model SRX-CA120-RTS Oxygen Sensor is designed for oxygen purity analysis and is a drop-in replacement to GPR-11-120-RTS sensor. Proprietary electrolyte formulation and unique anode structure ensures full utilization of Pb anode, thus providing longer life in 100 % oxygen without signal drift and minimizing frequent calibration requirement. Expected sensor life in air 10 years. Sensor is designed, developed and manufactured in the USA.