High Precision Sensor: Our air quality monitors use non-dispersive infrared (NDIR) technology and can track CO2 concentration, environmental humidity and temperature in real time. < p>Ventilation ReminderOur carbon dioxide detector has a 3-color LED indicator and an emotion icon to remind you of the CO2 level around. This not only helps maintain people's work performance, but also saves us from respiratory health problems. Portable CO2 SensorThis CO2 level detector is lightweight, the battery can be used for 6 hours after being fully charged. You can take it with you wherever you go. Easy to Use: The two buttons on the back of the carbon dioxide monitor implement all operations, including switching the temperature, backlight on/off and manual calibration.