Product Name: carbon monoxide / hydrogen sulfide detector Model: T40 (coal-safe type CTB999) Brand: Cisco Britain 

 * U.S. Patent, integrated one-button automatic calibration and calibration cover to adapt to changing exceptions such as the desert and the extreme Arctic climate 
 ? Continuous display of gas type, concentration and peak power saving, an AA / 5 AA alkaline batteries 500 hours 
 * The concentration level of the sound / light alarm, a timely reminder of the inspectors, light weight, only 98g 
 · C-US-UL (U.S. and Canada): EEx ia IIC T4, China Coal security MA # 20031923; China Measurement #: 01150210 

 Specifications: 

 * Shell: conspicuous color, impact composite material 
 * Size: 86 × 58 × 19mm 
 ? Sensor: Electrochemical principle 
 Measurement range: CO: 0 ~ 999ppm; hydrogen sulfide: 0 ~ 500ppm 
 CO: 0 ~ 1999ppm (MA); Resolution: 1ppm 
 ? Use conditions: Temperature: -20 ℃ ~ 50 ℃; Humidity: 15 ~ 95% RH (non-condensing)