Large Display Screen: This air quality monitor with large display screen allows you to see the detection data more clearly, you can get the results easily. Portable Size: This monitor is small in size and you can use it on your desk without taking up too much space on the desk, also easy to carry. Wide Applications: This CO2 monitor can be used at home, office, computer, hotel and other places. Built-in Multiple Sensors: This air quality monitor uses infrared detection technology, laser detection technology and electrochemical detection technology to show you accurate data. Four-color Alarm: There are four different colors to show the different quality of the monitored air: green means the air quality is good, and the colors from yellow to orange to red mean worse air quality. Temperature Unit Conversion: Temperature units can be switched between Celsius and Fahrenheit, and when the monitoring data exceeds the standard, a sound will be emitted to indicate this. Specifications: