This is an MSA Altair 4XR multi-gas detector designed to detect up to four gases simultaneously.The device is built for personal safety in high-risk environments such as oil and gas refineries and confined spaces.It utilizes MSA XCell sensors for rapid response times and features visual, audible, and vibrating alarms.The box indicates it is a rugged, portable unit used for monitoring combustible gases, oxygen, carbon monoxide, and hydrogen sulfide