Large-screen LCD, different font colors show different air quality Green 400-799ppm Yellow 800-1199ppm Orange 1200-1599ppm Red 1600-1999ppm Four colors above 2000ppm flash at the same time The product is small in size and easy to carry. The ventilation holes on the back not only accelerate the convection between the air and the machine, so as to achieve effective detection, but also provide a good heat dissipation effect. This product does not require calibration, can be tested at startup, accurate detection of carbon dioxide, used in greenhouse agricultural production, production warehouses, laboratories, homes, etc. Large-scale and practical, used for epidemic preventionand control, detecting CO2 concentration in the crowd, controlling the number of people, and avoiding the risk of cross-infection 1200mAh large-capacity battery, long working time, Type-C charging interface, easy to charge Colour: Black CO2 measurement range: 400-6000ppm Temperature measurement range: 0-50 Humidity measurement range: 0-99RH Battery: 3.7V, 1200mAh Product size: 90*70*35mm/3.5*2.8* 1.4 inches Item Weight: 117 g / 4.1 oz Package size: 140 * 125 * 41 mm / 5.5 * 4.9 * 1.6 inches Package Weight: 173 g / 6.1 oz Package: 1*Air Quality Analyzer 1*USB Data Cable 1*User Manual In order to control the number of people and avoid the risk of cross infection.