Product review (3 stars): Small, I A Little Disappointed  But For Some People, I Guess It Would Work
Well, I purchased 3 different brands of hygometer --- and this one  is the smallest by far, and tiny buttons to use to adjust things.  It did come with 2 batteries, only one is needed, one is a spare.  It came in a plain box, with minimal directions inside.  But when all 3 were put side by side, after a few hours, they were all reading different temperatures and humidity. The Temperatures varied by 1 to 2 degrees, and the humidity by 1 to 2 percent.  So, I don't know if this is the more accurate of the 3, or not.  But I think it is probably close to accurate --- but have no way to know.