I love this thing. My tank tep is now staying more regular. It also gives me peace e of mind that it won't allow the heater to bake my fish. I had one do that in the past. It was not pretty. The temp prob is small enough to hide in a corner.
My heater came with a kit and for a short while it seemed to work okay. But every week as I worked in my tank the thought kept nagging at me that the water was to hot. Most times it sat at 81 degrees. But in morning it gets some sunlight and so gains some heat, even so my heater would kick on and many mornings I would unplug it and remove the top. Then, on one of my visits to the Coop website I came across the Finnex Heater Control and in short order it was problem solved. Now we are all swimming at about 78 degrees and all is well!
Called Aquarium Co-Op about difficulties heating our small tank. The pre-set heater was passing it's target temp in a 5 gallon. Was happy to hear about this controller, and it has been working perfectly for us. Rapid delivery, great service!