I used a 3M Command Large picture hanging strip (15lb) laid horizontally just above the battery compartment in order to wall hang. The temperature and humidity are accurate.

Easy to set up, it is the right size and it runs on batteries so it can be placed anywhere, no plug needed.

I've had this for a week and really love it. I use two of the sensors to monitor my tortoise houses outside, and one to monitor the outside temperature. One house is 100 feet away, and the other is about 50 feet.

So far it works great. I was looking for something to automatically water my (basil) plants. I'm awful with plants so this probably won't end up being the key to their success as I'm hoping, but they will get water regularly now.