Product review (5 stars): Great for use in safes as well
I tried this in a gun safe. I was surprised to find that the Bluetooth signal did reach outside the fire/waterproof safe. Yeah it cut down the range, but since I would walk past it every day, the range was fine at about 15ft. Its designed to pair to your phone for a music case which would extend the range to about 30ft.
Anyway, inside the safe was the place I wanted it, and it monitors humidity and temperature. I wasn't too worried about the temp, but I I always worry about humidity inside a safe of any kind, This handy little gadget lets me sleep secure in the knowledge that my stuff is not rotting away.