4 in 1 Gas Detector O2 H2S CO Combustible Carbon Monoxide Oxygen Flammable Gas Analyzer Toxic Gas Harmful Gas Leak Detector Features:  Detect 4 kinds of gas: carbon monoxide(CO), hydrogen sulfide(H2S), oxygen(O₂) and combustible gas(LEL).  Continuously monitor the CO, H2S, O₂and LEL gas concentration in the surrounding environment with professional and accurate measurement.  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.  Can connect to a sampling pump to operate in closed place.  Can be widely used in shipping, mining, oil exploitation, chemical, gas pipeline, tunnel construction, coal, metallurgy, paper, fire, municipal, textile and other industries. Specifications:  Material: ABS Plastic  Display: Color LCD Backlight Display  Screen Size: 47 * 38mm / 1.9 * 1.5in  Sensor: Electrochemical Principle  Duty Cycle: 2 Years  Explosion Proof: √  Protection Grade: IP65  Detection Gas: Carbon Monoxide(CO, Hydrogen Sulfide(H2S), Oxygen(O₂), Combustible Gas(LEL)  Measurement Range: CO: 0~999ppm, H2S: 0~500ppm, O₂: 0~30%VOL, LEL: 0~100%LEL  Resolution: CO: 1ppm, H₂S: 1ppm, O₂: 0.1%VOL, LEL: 1%LEL  Accuracy: CO: ±10%, H₂S:±5%, O₂: ±3%FS, LEL: ±5%FS  Alarm: Sound & Light Vibration Alarm (Alarm value can be set)   Alarm Point: Low Alarm Point CO: 35ppm, H2S: 10ppm, O₂: 19.5%VOL, LEL: 10%LEL    High Alarm Point CO: 70ppm, H2S: 20ppm, O₂: 22.5%VOL, LEL: 20%LEL  Alarm Sound: up to 80dB   Response Time: Instantaneous  Warm-Up Time: < 20 Seconds   Continuous Operation Time: 6 hours(slightly vary with working condition)  Power Supply: 1 * Rechargeable BL-9C Lithium-ion 3.7V 2500mAh Battery (Built-in)  Operating Temperature: -10~50° / 14~122°   Operation Humidity: 15%~95%RH (non condensation)  Product Size: Approx. 140 * 75 * 43mm / 5.5 * 3.0 * 1.7in  Product Weight: Approx. 249g / 8.8oz Package List: 1 * 4 in 1 Gas Detector 1 * USB Line 1 * Storage Box 1 * Use Manual (English)