I will put this in the I cannot beleive it actually works catagory.
I saw these in the hardware section of Walmart last night. They are white, about the size of a pager with a clip on the back with a magnet. I will probably tear off the clip and attatch it with Velcro.
I out the batteries in them and looked at the readings. One was reading 68* and 35% humidity and the other was 62* and 38%. I look at the paperwork for calibration instructions, and there are none
I am thinking to myself, I just wasted $14.
I tossed them into my humidor with the calibrated hygrometer. I open the top an hour later and they are reading 68* and 40% humidity. At least the temperature matched. I figured I would leave them in overnight, and when I check them this morning, 68* & 60% humidity, Matching perfectly with the calibrated hygrometer.
That was a pleasant suprise!!! They actually worked. And to think I would have bought one for $25 at Radioshack if the were in stock.