Product review (5 stars): After one year, even more useful than I imagined
I purchased several of these over a year ago and I have no reason to doubt their accuracy.  They last for more than a year on alkaline batteries.

I recently found a new use - in my refrigerator.  I used them to monitor the temperature in my freezer and refrigerator compartments for troubleshooting and setting temperature.  Use lithium batteries for the freezer compartment as required for below -4 degrees Fahrenheit.  The Honeywell TM005X Wireless Indoor/Outdoor Thermo-Hygrometer unit reads them through the case!

I have been using these to monitor temperature and humidity in crawl spaces, attic and basement.  I highly recommend this item and the base unit Honeywell TM005X.