Features: Air quality monitor: Carbon dioxide monitor can detect carbon dioxide, temperature and humidity. It is usually used in places with high carbon dioxide concentration, such as schools, office buildings, factories, hospitals, hotels, etc., to test the air for health and safety of your environment anywhere. High precision: large LCD screen, using NDIR (non-dispersive infrared) sensor, is a new type of infrared sensor, working fast and stable. Compared with old-fashioned chemical sensors, it is not affected by temperature or other conditions and has an audible alarm function. Data logger: for touch button operation, built-in storage, continuous data recording, tracking up to 7 days of carbon dioxide concentration, temperature, humidity trend data, and displaying the maximum and minimum values. Specifications: Material:ABS Size:Approx.8x13cm/3.14x5.11inches Color:Black Package Includes: 1 Set Air Quality Monitor note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.