3 In 1 Carbon Dioxide Monitor Detector: One for 3 functions, you can intuitively understand the air quality you breathe with air quality including CO2, temperature and humidity High-precision: The sensor module with TVOC sensor to accurately monitor carbon dioxide, highly recommend to use it with USB charger Visualization:The CO2 monitor with intelligent color display screen will indicator light that changes color according to the different degree of carbon dioxide concentration allows you to easily grasp the current state of carbon dioxide concentration in the air Wide Application:Portable Co2 monitor with compact design suitable for monitoring the air quality at home, schools, office buildings, hospitals, restaurants, shopping malls, factories, hotels, laboratories etc Why You Need It: Perfet gift for him/her/ kids, with the air quality monitor, you can definitely know what is your environment be like and improve it according to the actual situation