Carbon dioxides monitor with 3 detection values: CO2 Temp Humidity Features: Detection values for carbon dioxide, temperature & humidity. This air quality monitor has a colour display screen to see the detecting data clearly. This CO2 monitor can be used in your home, office, desktop, hotel, etc. This air quality monitor uses infrared detection technology, laser detection technology and electrochemical detection technology to show accurate data. There are four different colours to show the different qualities of the air being monitored: Green means the air quality is good and the colours ranging from yellow to orange to red mean a worse air quality is present. The temperature unit can be switch between degrees Celsius and Fahrenheit. Specifications: CO2 detecting ranges: 400-5000PPM Recharging method: USB 500mA Type-c interface Battery: 1 * lithium battery, 1200mAh (included) Item size: 90 * 70 * 35mm / 3.5 * 2.8 * 1.4in Package size: 118 * 115 * 48mm Package weight: 200g