1Large Screen: The carbon dioxide detector is equipped with a large screen. Different font colors show different air quality. Green flashes at 0999ppm, and yellow flashes at 10001999ppm, orange flashes at 20002900ppm, red flashes at 30003999ppm, and the above 4 colors flash at 4000ppm. 2Accurate Measurement: This air quality monitor adopts a special premium electrochemical detection module, which has good accuracy, stable performance, strong anti interference ability and low consumption. 3Ventilation Hole Design: The left and right hundreds of ventilation holes not only accelerate the convection between the air and the machine, so as to achieve effective detection, but also provide good heat dissipation effect. 4Easy to Use: The carbon dioxide tester does not need calibration, and can be used to test the air quality when starting up, the can well detect the carbon dioxide. 5Long Service Life: This infrared carbon dioxide detector is made of premium ABS material, which is compact and not easily be damaged, and can be used for a long time.1 x Host1 x USB Line1 x Instructions