Home Safety Guard-- The air quality monitor can monitor carbon dioxide in real time. Our detector with multiple functions can also detect indoor temperature and relative humidity at the same time. The best choice for your comfortable living and office environment. Exquisite Design-- Exquisite size 70*80*35mm. A perfect decoration and practical tool for your bedroom and office. With the special coating on the surface of the screen, you can also use it as a mini vanity mirror. High Precision Measurement-- The detector adopts non-dispersive infrared technology with air vents on the back and a built-in NDIR infrared sensor, which can accurately detect the CO2 gas concentration, ranging from 400 to 5000 PPM. The accuracy can reach 1 PPM. Triple Indication Color-- Built-in 3 color indicator lights. Red, yellow and green colors represent poor, normal and good air quality conditions respectively. You can intuitively understand the quality of the air you breathe. Your best health monitoring assistant. Portable and Energy Saving-- Lightweight than 150g and easy to carry.A built-in rechargeable battery is inside.It could also be charged by USB cable.Fully charged before using in just 2-3 hours.