SRX-CTR32 Diving Oxygen Sensor is a replacement for Analox Mini O2 (1x16mm thread), Analox 9121-0 sensor, Teledyne R-33D1-NUV, R33D-1, PSR-11-37-D2-1, IT Gambert D-09 and NuvAir O2 stick. Proprietary electrolyte formulation ensures full utilization of Pb anode, thus providing longer life without signal drift and minimizing periodic calibration requirement. Sensor is designed, developed and manufactured in the USA.