Dual display of Carbon Dioxide (CO?) concentrations and Relative Humidity, Temperature, Dew Point, or Wet Bulb Automatic Baseline Calibration function Data Hold, Auto Power Off (with disable), Low battery indicator Tripod mount (tripod sold separately) Maintenance free NDIR (non-dispersive infrared) CO? sensor Audible CO? warning alarm when concentration level exceeds high user set point Min/Max CO? value recall function Includes software and cable for on-line (real-time) datalogging to a PC Specifications Carbon Dioxide 0 to 9,999ppm Relative Humidity Range 10 to 90%RH Dew point temperature 99.2 to 118"F (-72.9 to 47"C) Wet Bulb Temperature 12.2 to 118.8"F (-11 to 48.2"C) Weight 6.4oz (181.4g) Dimensions 8.3x2.4x1.6in (211x60x40mm) Temperature range 14 to 122"F (-10 to 50"C)