Product review (4 stars): Cheap, reasonably quickly delivery, and reasonably accurate -- used in a wine fridge
PROS: really cheap, meets the accuracy ranges specified, and delivered fast compared to estimates (arrived in 12 days from China despite Amazon's estimate that it would arrive in at least a month). Temp readings are +/1 degree tolerance and humidity readings are +/- 5%.

CONS: Mediocre precision on humidity reading. As you can see in the picture, the temperatures are pretty much lined up across the two digital units I bought on Amazon and an inexpensive analog gauge that I already had. Humidity readings across the three are fairly different. The digital units are within 10 degrees difference (assuming one could be 5 degrees skewed up and one could be skewed 5 degrees down) but the analog unit is above both digital units. So clearly there is a measure of imprecision at this price point. I won't dock the review too much because it still meets the manufacturer's stated tolerance level, though.

I bought two digital units for my thermoelectric wine cellar/fridge. I have one closer to the top of the unit and one closer to the bottom, in case there are any significant temperature variations.