Product review (5 stars): A handy and accurate way to check humidity and temperature.
I have one of these monitors in each of our rooms.  I can quickly tell the temperature and humidity in each room.  I use them to monitor my kids rooms during the winter to make sure that the heat doesn't make their rooms too dry leading to nasal issues while they're sleeping.  If the humidity drops too low, I turn on a humidifier until it's back to a comfortable level.  I also use one in the attic and another in the basement to keep a check on the humidity so I don't have mold issues.