Product review (5 stars): This CO2 meter is the best investment ever for me
This CO2 meter is the best investment ever for me.  Plug it in and in 5 seconds you have the CO2 parts per million (PPM) reading.  My bedroom read 1500 (impacts cognitive thinking), opened windows and put a fan on the ledge to bring in outside air (CO2 only 450 ppm) and now in two days my home reads ~490 PPM-a safe level, already notice the difference, clearer thinking, etc..