The high-definition LED screen enables you to read data faster and more . There are 4 different color on the screen indicating CO2 concentration levels: green for healthy, yellow for attention, orange for ventilation and red for danger. This allows for a quick identification of the surrounding air quality. use, put the CO2 sensor in the vent for 5-10 minutes for data calibration, if the air quality changes, wait 35 seconds for the detector to sense the change Using NDIR non-scattering infrared sensor, CO2 detector has stable performance and high precision Carbon dioxide detector real-time monitoring: real-time detection of indoor environmental quality, measured by three key indicators - carbon dioxide, temperature and humidity, comprehensive indoor air quality, to breathing health With a simple and generous design, mini size makes it easy to carry out, and a built-in 1000 mAh rechargeable battery can continuously work for 8 hours, allowing you to check the air quality anytime and anywhere. This portable CO2 monitor supports USB charging and has a low battery indicator. This mini carbon dioxide monitor is used for grow room, travel, camping, , , hotels, parties, wine cellars, kitchens, bedrooms, offices, schools, agricultural planting, indoor gardens, etc. Type:CO2 Detector Type:Carbon Dioxide Concentration Detector Colour:black Material:ABS Size:73 x 73 x 18mm Package Contents: 1X CO2 Detector 1X USb Cable 1X English manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.