Product review (2 stars): Sorry - not reliable enough for a humidor
Just would not work in my humidor ( desktop with good seal).  Wanted it to work as I had sucessfully used a LaCrosse unit for +5 years before it quit receiving humidity.
I tested the reciever inside an airtight plastic container via salt method and it read a perfect 75%.  Had two regular hygometers for a double check, both reading 75% as well.  When set in the desktop humidor readout dropped to 65% - other hygometers reading 74%.
Removed batteries, reset and tried 3 x with similar results.
Going to go with a PushSensor unit - much better reviews.