Carbon Dioxide Sensor Meter Tester 9999ppm CO2 Temperature RH Measurement Parameter : Carbon Dioxode (CO2) Temperature Humidity Dew Point Wet Bulb Temp. Carbon Dioxide (CO2) Measurement: 0~9999ppm Temperature Measurement Range : -10 ~50.0C (50.0~122.0F) Relative Humidity Measurement Range : 0.1~99.9%RH Power Supply : 6 x AAA batteries (included in set) / AC/DC adaptor (not included in set)