Portable Vehicle CO Detector. Thermal meter model : 25CTH01 Detection range : 0–900PPM Working voltage : 3V(105V * 2,7#,Alkaline included ) battery warm up time: 120s Data refresh frequency 2s Working humidity 0-95% RH Working temperature 10–50 ^C Operation is subject to the following two conditions This device may not cause harmful interference This device must accept any interference received including interference that may cause undesigned operation . Brand new in box