Can connect to a sampling pump to operate in closed place. It adopts advanced integrated circuit technology, embedded computer control, high-quality gas sensors, with excellent sensitivity and repeatability. Intelligent voice, Sound & light vibration alarm works when one of the CO, H₂S, O₂ & LEL gas concentration reaches the level of the alarm. Can set automatic shutdown time and concentration of alarm value. Large color LCD display with backlight for easy reading. Detect 4 kinds of gas: carbon monoxide(CO), hydrogen sulfide(H₂S), oxygen(O₂) and combustible gas(LEL). Continuously monitor the CO, H₂S, O₂ and LEL gas concentration in the surrounding environment with professional and accurate measurement. It uses dot matrix LCD display to support Chinese-English interface and Chinese-English voice prompt, so that users can quickly understand the product and use and maintain it simply. High-strength engineering plastics, good seismic resistance, high strength, high-grade atmospheric appearance and dust-proof, waterproof and explosion-proof function. Stainless steel buckle, the back with a shelf can be fixed on the outside of the tooling, firmly clamped and not easy to fall. USB charging interface, 3.7V/1800mAh lithium battery, convenient and fast, fully charged can be used continuously for more than 10 hours. Can be widely used in mining, oil exploitation, chemical, gas pipeline, tunnel construction, coal, metallurgy, paper, fire, municipal, textile and other industries., Manufacturer: Jnchdghwa