Bosean has always strictly implemented the ISO9001,CE,ATEX, ROHS quality management system. We adhere to the high standards of product quality, strict requirements, adopting the world-class production equipment, advanced management and production experience, developing the high-quality testing equipment. Features 1. SENSOR: High quality electrochemical sensors Made in the UK. Oxygen (O2), Carbon Monoxide (CO), Hydrogen Sulfide (H2S) and Combustibles (LEL). Comes FACTORY CALIBRATED. Turn ON and GO. 2. DETECT: Detection error better than 5% F.S. and response time: T<30s. Zero and span calibration options. 3. ALARMS: Adjustable audio, visual, and vibration alarms alert when preset levels are reached. Alarm digital time stamp and logging. 4. STRONG: Robust design made of high strength ABS and Anti-slip grip rubber. Waterproof, dust-proof and explosion-proof exceeding Exib IIB T3 Gb. Specification Gas type: Oxygen/carbon monoxide/hydrothion/combustible gas( O2/CO/H2S/LEL) Gas measurement range: O2: 0~30%vol, CO: 0~999umo/mol(ppm), H2S:0~100 umo/mol(ppm), EX (combustible ):0~100%LEL Resolution:0.1%vol/1umo/mol(ppm)/1% LELLow/High alarm/Alarm setting: Yes 4 Alarm metods : Sound Alarm, Light flashing, Vibrating alert, Screen shows, adjustable alarm values, alarm sound up to 80db Operating temperature: -2050(except LEL is 0~40C) Operating humidity:95%RH (no dew) Display: 2.4 inch HD display Power: 3.7V li-battery(Built-in) Battery runtime: 6-8 hours or so. Product Net Weight : 400g (with battery) Size : 145mm69mm28mm (L W H) Packing List: 1 x 4 in 1 mutil gas monitor 1 x English User manual 1 x Charging adaptor 1 x USB charging cable 1 x Calibration cover 1 x Metal aluminum box 1 xCertificate