Features 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. Specification Item Type: Carbon dioxide detector Material: ABS, electronic components Weight: Approx. 192g/6.8oz Product Size: 9x7x4cm/3.5x2.8x1.6in Carbon Dioxide Detection Range: 400-5000ppm, accuracy: 1ppm Temperature Measurement Range: 0-50℃, accuracy: ± 1℃ Humidity Measurement Range: 0% - 99%RH, accuracy: ± 2%RH Battery: Built in rechargeable lithium battery model 18650, capacity 1200mAh(Shipped with built in battery) Package List 1 x Carbon Dioxide Detector 1 x Data Line 1 x Instructions