Product review (1 stars): One Star
Inside and outside temperatures and humidity do not match when the outside sensor is placed  right beside the base unit (see photo).  The inside and outside sensor were within an inch of each other for over 12 hours and there was a 6 degree temperature variance and a 15 degree humidity variance.  So I took out all of the batteries, after 5 minutes I replaced the batteries in the sensor, then replaced the batteries in the base and the same thing happened.  The description on Amazon says "5 AA batteries required" but I can only find where to put 4 (two in each unit).  For the life of me, I can't find where to put the 5th battery.  This equipment is useless to me, as I want to monitor the humidity in my crawl space.  I am going to try to return it as soon as possible.