Features: It can accurately and quickly detect the indoor CO2 content to protect your health. At the same time, it provides real-time monitoring of indoor temperature and humidity. Adopt infrared detection technology, high measurement accuracy, fast response. It has 4 colors indicator lights to display real-time carbon dioxide concentration value. Different color indicator lights will flash according to the carbon dioxide content, making the air quality more intuitive. Small size, easy to carry and use. Built-in 1200mAh large capacity battery, long endurance time. It can help us to detect air quality in school, office, restaurant, gym, cinema, greenhouse, warehouse, etc. Specification: Type: Carbon dioxide monitor detection technology: Infrared detection technology Sensor: Infrared sensor CO2 detection range: 400~5000ppm CO2 Indication:  0-799ppm: Green light flashing 800-1199ppm: Yellow light flashing 1200-1599ppm: Orange light flashing 1600-1999ppm: Red light flashing Above 1999ppm, 4-light flashing Screen: 2.8 inch LCD screen Charging port: Type-C Battery capacity: 1200mAh Operating voltage: 5V Item size: 9 * 7 * 3.5cm /3.54 * 2.76 * 1.38in Item weight: Approx. 106g/3.74oz Packing list: 1 * Air monitor 1 * Data cable 1 * User manual