Product review (5 stars): Good Product, Great Service!
This meter has been very helpful with monitoring the CO2 levels at work, and tends to be an good indicator of overall air quality.  I had a minor problem with the particular unit I received, one of the digits on the display wan't working. (a minor issue, and probably a rare one at that).  Customer service got me squared away with lightening speed.  Would definitely order this product again, or other products from this seller (CO2Meter).