Product review (3 stars): Reading is consistently 4 degrees low
I ordered a pair of them about 3 weeks ago.  The summary is - they read 4 degrees low (Fahrenheit) compared to my house thermostat and a local clock / thermometer.  They arrived on time and were packaged well.  I like the display, easy to read.  The high and low for the day appear to be right.  We have a lower temperature at night, and the "low" appeared to be accurate (but 4 degrees low).  After they acclimated to the house temperature I balanced them on top of the house thermostat.  They both read 4 degrees low.  I then placed them next to my clock / thermometer and they read 4 degrees low.  The humidity reading was 2% different between them when I had them side by side.  I will have to watch the humidity for a while to determine whether it is useful.  I give the product 3 stars due to the temperature difference.  I think I can use them because they are consistently 4 degrees low and I can automatically make the adjustment when I view one of them.