Product review (5 stars): Great price and great quality....
Favorite monitor of mine,  I have turned off the more expensive monitors in my grow room and am manually controlling my CO2...  There is an alarm on this and once I read the direction on how to turn that off I was good to go.  This is very accurate.  I have 2 of them in my nursery so I know how the air is circulating.....  Great price and great quality....