1、3 Functions: This device has 3 functions, that is carbon dioxide detection, temperature detection and humidity detection, so that you can intuitively understand the air quality of the living space.2、Semiconductor Sensor: The carbon dioxide detector uses semiconductor sensor to monitor carbon dioxide, with good accuracy, stable performance, strong anti interference ability and low consumption.3、Large Screen: The air quality monitor is equipped with a large screen, and different font colors show different air quality, so that you can check the air quality at any time.4、Left and Right Ventilation Holes: The left and right ventilation holes not only accelerate the convection between the air and the machine, thus achieving effective detection, but also provide good heat dissipation effect.5、Widely Applicable: This carbon dioxide tester has a long service life and a wide range of applications, such as schools, hospitals, restaurants, shopping malls, offices, homes, etc.