Extech Instruments CO240 Handheld Indoor Air Quality and Carbon Dioxide Meter

Dual display of Carbon Dioxide (CO2) concentrations and Relative Humidity, Temperature, Dew Point, or Wet Bulb Maintenance free NDIR (non-dispersive infrared) CO2 sensor Audible CO2 warning alarm when concentration level exceeds high user set point Min / Max CO2 value recall function Data Hold, Auto Power Off (with disable), Low battery indicator