My wife has had a headache for the past few months and I decided to find out if elevated CO2 levels could be the cause. Well, I was surprised at how much CO2 accumulated in our house. A quality monitor like the MOES WIFI Air Quality Monitor CO2 Detector with Temperature is very useful! I like that this monitor can switch from C to F as I use F temperature here in the US. It is also equipped with a rechargeable lithium battery with a capacity of 2400 mAh, which makes it ideal for camping trips with my propane heater. Carbon dioxide or CO2 is a harmless gas in the atmosphere, but when its concentration increases inside a home, it can cause health problems for the people living there. Humans and animals exhale CO2 as a natural function of respiration. Therefore, when a house is overcrowded and there is insufficient air exchange with the outside environment, CO2 levels can increase. Ground cover is a process that can occur in homes built on old agricultural land when wet weather causes the soil to expand and gases, including natural amounts of CO2, to be released into the home. Inadequate air conditioning can also contribute to increased CO2 levels. Another source of increased CO2 emissions is the use of fossil fuels in the home. Therefore, it is very important to have the tools to monitor your situation and alert you when something is wrong. Attached are some photos for a closer look at the device. This is USBC, which is great! The quality of the screen is bright and very legible day and night.