Product review (3 stars): Battery hog
While the unit functions well enough, it's a battery hog - running through batteries much, much faster than my ancient but still very functional Radio Shack indoor/outdoor digital thermometer.  When the batteries do die (as they do with disturbing frequency) the only way you know they're dead is when you notice that the temp/humidity numbers haven't changed in a day.  There's no other reliable indicator of battery failure that I can see.

We use well rated name brand AA batteries in the unit.  I would try other well rated indoor/outdoor thermometers before buying this one.