Carbon dioxide detector: real-time and accurate monitoring of CO2 concentration, ambient humidity and temperature, with date and time display, and the data is updated in real time every 4 seconds. Independent semiconductor sensor: for measuring CO2, temperature and humidity, large color screen, LED digital display, intelligent backlight, soft eye protection, intuitive reading, clearer display, 24-hour real-time monitoring. Long battery life: use 3 AA batteries (you need to bring your own) or use the interface USB TYPE-C data cable to power. The battery life can last up to half a month. Automatic alarm system: When the CO2 concentration exceeds 1000 ppm, an alarm will be issued to remind you to ventilate the indoor environment in time. Lightweight design: small size, easy to carry, and can be used directly by connecting USB cable. Can be placed anywhere: schools, offices, bars and restaurants, homes, cars, etc.