Havent used it yet but I am sure it works good

Nothing beats the price of this one. It does the job right!

This has been great, works fine in my 66 quart monotub bulk grow. I picked up some sticky magnetic tape at OfficeMax and now I can move it anywhere in my tub. I just place magnet on outside of bin to keep it in place! Great buy at $5

Small, works well.

Got one of these last year and it works great. I glued a magnet on the back of it and then use one on the outside of the tub to hold it up. Takes a couple of watch batteries that last a long time, and its easy to read.