Wide Applications: This CO2 monitor can be used in your home, office, destop, hotel and other places. Portable Size: This monitor is small in size and you can use it on your desk without taking up too much desk space, also easy foryou to carry. Large Display Screen: This air quality monitor with a large display screen for you to see the detecting data more clearly, you canget the results easily. Built-in Multiple Sensors: This air quality monitor using infrared detection technology, detection technology and electrochemical detection technology to show you the accurate data. Four Color Alarm: There are four different color to show the different qualities of the air being monitored: The green means theair quality is well and the colors ranging from yellow to orange to red mean worse air quality., Manufacturer: HIJYMNZPQ