Product review (5 stars): but very good buy.
We bought a humidifier and needed to know where we were at with the humidity levels. This is very accurate, from what we can tell ie, taking a shower, we know it's humid and without it, very low (live in colorado). This lets us see where we are and whether we need to run the humidifier higher or lower, etc. I was somewhat hesitant based on price and reviews, but very good buy.