Product review (1 stars): Grossly inaccurate
I purchased this about four years ago because I was wanted the outdoor humidity sensor feature.  I had previously been using a Taylor indoor/outdoor wireless thermometer and was very pleased with its performance and accuracy.  But I wanted to see the outdoor humidity as well.

I installed the batteries and placed the indoor unit next to another digital indoor humidity sensor and an analog dial humidity sensor.  The indoor and analog sensors agreed, the Acu-rite indoor reading was about seven percentage points lower.  Now, after a number of years of use, I have found that the outdoor humidity reading is consistently low by about 10 percentage points, particularly at high temperatures, when it counts the most.  I consider this error unacceptable, even for a home unit, and do not recommend this product.