Product review (1 stars): Quality Control Problems
I don't like giving low ratings, and I see many buyers are happy with this unit, but there must be a bad lot.

I bought one a week ago and the outdoor humidity reading was stuck on 1%. Actual humidity here in Tucson is more like 15% according to various weather stations, so that ain't even close. Even Death Valley at its driest isn't  1%.

Sent it back, and 2 days later had the replacement in hand. Amazon is always good about that.

But, this replacement is also stuck on 1%.  Identical to the first one, the indoor humidity reading seems okay, about 24%, and the indoor/outdoor temperature readings are right on. By the way, I tried putting the send unit right next to receiver, just to make sure it isn't an interference problem, no help.

There's probably a potentiometer inside that I could adjust to fix this, but if I open it up, that would theoretically void the warranty, so I won't mess with that. I'll try something else.

Previously I had a Taylor indoor/outdoor that I got from  Ace Hardware for ten bucks. It lasted almost 15 years, but I see lots of buyer complaints about its equivalent unit here on Amazon. Chinese build quality is so hit-and-miss. It might last a day, might last ten years, who knows?