Product review (5 stars): Could not be more pleased!
I was somewhat skeptical as to whether this would have the range to pick up sensors INSIDE the refrigerator and freezers located downstairs, and in the garage, which is a long way away.  But this thing does!!! It works better than I had ever hoped!  I put lithium ultimate batteries in all the sensors, and the cold doesn't affect them at all.  Accuracy is superb, and the app is one of the best I've ever seen.  If you have freezers and fridges and whatever which need temperature and humidity monitoring from afar, this is THE SYSTEM to get!  Highly, highly, HIGHLY recommended!!!