Review on Upgraded Refrigerator Thermometer Wireless Temperature by Heather Shaw

I have used this to wirelessly monitor my two freezers running at 0 degrees plus or minus two degrees. My first block randomly fluctuated between -20 and 20 degrees, my second block (I was hoping mine was just bad so I got her to trade it) randomly between -15 and 12 degrees or something. I assume this is an improvement? The device was within 6 feet of the sensors. Basically they are useless if you need reliable readings. Yes, and all of my actual temperature readings were confirmed by a non-wireless device that was stable at 0 degrees. Don't buy this junk.