Product review (1 stars): Only buy this if you are in a hurry to fill up your local landfill.
I bought it to use the remote sensor in my cigar humidor so I wouldn't have to lift the lid every day to check the humidity.  The readings were never even in the same ballpark as reality.  I compared it against my calibrated digital hygrometer in the humidor. It swung wildly up and down, but at its best it was at least 20% off on humidity and 10 degrees in temperature.  Usually it was more like 30 - 40% off.  I had figured that if it wasn't accurate enough for the humidor, I could at least use as an indoor/outdoor thermometer as it is intended.  However, it is so inaccurate that's its useless even for that.  Even the "indoor" part is usually pretty far off.  Unfortunately, I kept it too long (3 months) to return it, hoping it would eventually settle down, but it never got any better.  I hate to be wasteful, but since it serves no function other then taking up physical space, it is going in the garbage.  Do NOT waste your money.