Based on the standard ALTAIR single-gas detector, but with additional features and functionality, ALTAIR Pro toxic gas and oxygen detectors combine reliable detection and LED/audible/blinking/vibrating alarms with clear, backlit LCD displays. Electrochemical sensors measure concentrations of toxic gases (chlorine dioxide, hydrogen cyanide and phosphine) or percentage of oxygen. Designed for superior protection against dust and water, excellent shock resistance and radio frequency performance.