【High Accuracy】The CO2 monitor / Carbon Dioxide Detector adopts an advanced NDIR sensor for fast, accurate, and continuous monitoring of CO2 concentration (carbon dioxide concentration), temperature, and humidity. 【Visual Alarms】Easily detectable CO2 indicator light (green, yellow, red) for real-time assessment of CO2 concentration. 【Audible Alarm】The CO2 detector triggers the DIDI alarm at a concentration of 1000-5000 PPM; of course, you can also turn off the sound temporarily or permanently, depending on your preference. 【Automatic Calibration】During operation, the CO2 monitor is automatically calibrated according to the ambient air concentration. If necessary, you can also calibrate it manually. 【Where to Use】Houses/apartments, bedrooms, cars, offices/meeting rooms, schools, hospitals, vegetable sheds, warehouses, etc.