Product review (4 stars): Impressive!
I've had this system for 6 weeks now and continue to be fascinated by how well it is working.  One sensor is in a freezer in the basement and another is in the meat keeper in the refrigerator (the third measures room temperature in a bedroom).  The receiver is on the second floor at the opposite end of the house from the freezer a couple of feet from my router.  The transmissions penetrate the metal freezer and refrigerator walls with little trouble.

Signal loss is infrequent, once every 2 or 3 days for the freezer, approximately weekly for the refrigerator, and corrects itself with no intervention on my part.  An alarm regarding signal loss comes to my cell as programmed.  The temperature alarm capabilities are very versatile and work reliably for alarm conditions I have created and tested.  I docked the system 1 star because the installation instructions are a bit sketchy and incomplete.  But once you get past installation all is well.