Product review (4 stars): ThermoPro Hygrometer Indicates Humidity Level and Temperature Of Room
I wasn't sure what the humidity was in the bedroom. So I bought this hygrometer. The price was good and the product seems to be
working just fine. I have chronic dry sinuses and use a cool mist humidifier but didn't want to run it if it wasn't too dry in the room. So the
gauge helps me to know if I need to turn on the humidifier if humity is below 40. Includes a free battery, how thughtful.
 (Note: Use distilled water in a cool mist humidifier, otherwise you will have a white powder mess from the minerals in tap water.
  YES, I used tap water and I had a terrible mess to clean up!  I buy a gallon bottle of  distilled water from
  Dollar General for only a dollar. It is located near the bottled drinking water. We don't recommed you drink distilled water either,)