1Advanced Sensor: The dual channel infrared sensor provides high accuracy detection and fast measurement response. Can be connected to USB for charging. 2Real Time Monitoring of Carbon Dioxide: The detector is designed to monitor the concentration of carbon dioxide in real time. It can also measure the surrounding temperature and humidity. 3Easy to Carry: This easy to carry air quality meter can help monitor air quality in homes, cars and offices. Support 3 AAA batteries (not included) for power supply. 4Easy to Use: With just one button, you can easily complete all operations, including opening and closing, switching between Fahrenheit and Celsius, and calibration. 5Auto Calibration: The device will be automatically calibrated within the first 24 hours after monitoring start, and it will be calibrated every 7 days thereafter. After calibration, the carbon dioxide value will be read as 400PPM.