Product review (1 stars): Not recommended - accuracy is way off
This rating may be a little harsh, but I bought two of these for my daughter's rooms for our very dry winters to make sure that our humidifiers are working properly. I just happened to have them together and realized that they were 5 percentage points off from each other. I threw away the packaging so couldn't return them. Will have to do some more research to find ones that are more accurate.