Product review (5 stars): Very Informative
I originally ordered this in error....I was looking for a CO (carbon monoxide) meter and ordered this by mistake. However once I received it I decided to give it a try. Much is known (or written) about the dangers of CO but I didn't know much about the issues associated with high CO2 levels. Turns out the CO2 levels get very high in my bedroom at night. I have several dogs and of course they pile on especially when it's cold and I usually close the door. Long story shortened, that is contributing to the higher levels and also to my headaches. It's an easy fix, just open a window but I hadn't given that much thought before because the room was cool enough to be comfortable without doing so.

So, in short,  I decided to keep the meter... I no longer wake with a headache and it gives me peace of mind.

I've since ordered a CO meter from the same company.

I think both are an excellent investment!