Product review (5 stars): Good price, good equipment.
I purchased these multiple sensors to monitor the rooms in my home as we don't have central heating/cooling.  Rooms are heated by electric baseboard heaters, that are not on individual thermostats.  Upon opening these sensors and getting them up and running, the main panel and the sensors all showed the same temperature and humidity within 10 minutes.  After several weeks, I noticed that one sensor was showing the exact temp and humidity all the time, day or night, no variation at all.  I removed the batteries to "reset" the sensor, and it began working properly again and has been normal for 6 days now.  Earlier reviews indicated problems, but I've not seen any of them except for the one that got "stuck", and as noted, it's working fine now.  I believe the sensors to be accurate, and I would recommend this system if you are looking for a good way to monitor your home.
UPDATE AFTER 60 DAYS:
So, overall these units are working exactly as they should.  During the last 60 days, the earlier mentioned sensor continued to "get stuck" about once a week, so I exchanged it with another unit that was closer to the receiver.  That completely solved the problem, all sensors are working properly and giving updated readouts in a reasonable time.  On one occasion, the main receiver "got stuck" and needed to be reset as it wasn't updating.  That was about 40 days ago, and it's still working fine.  I continue to recommend this system to monitor temps in your home!!