Product review (5 stars): Inexpensive, Accurate, and Incredibly Functional
There are a number of negative reviews of this product and the primary complaints are accuracy and failures to function. I have had the same unit for over 2 years and have gifted units to my parents and my sister's family. The remote sensor transmits effectively from any practical distance. The display shows the temperatures and humidity inside and out in an easy to read format. It also shows the outdoor temperature trend in an easy to read form which is a neat feature. Folks who complain about the unit's operation may have gotten a lemon and should exchange it. Accuracy is always close to the media reported temps and humidity. I bought my unit at one of the big home improvement stores and paid $20 on sale. When xmas came around, I bought 2 more units for family and paid $25 so the Amazon price seems higher than it should. Nevertheless my family deemed it one of the best and most practical christmas presents ever!

Update 11/22/14: Having owned several, gifted a few, and moved with these on more than one occasion, I have concluded that erratic behavior or performance failure can be primarily attributed to where you locate the outside sensor. I made the mistake of temporarily placing it in a southern facing window during the last move and when I got around to it, I relocated it to a covered northern location. Too late, damage was done, and the external sensor lost all accuracy. The one hiding under the deck (away from the sun and elements) continues to chug away faithfully. I will buy another but will be more mindful about following the manufacturer's instructions!