Indoor Air Quality Tester, Calibration Certificate Type NIST, Digital Display Screen Type LCD, Features Ergonomic, Overmolded Case Design, Low-drift NDIR CO2 Sensor for Stable and Accurate Readings, Sampling Function Records Multiple Point Measurements, Includes Carrying Case, Maximum Carbon Dioxide Measured 5,000 ppm, Maximum Carbon Monoxide Measured Not Applicable, Maximum Dew Point Measured Not Applicable, Maximum Oxygen Measured Not Applicable, Maximum Pressure Measured Not Applicable