Review on SZELAM Submersible Aquarium Temperature Controller by Kevin Taharka

I dared this thermometer and was NOT disappointed! It works exactly as expected in my 3 gallon betta tank. I set the temp and it came up to temp and HOLDS the water at that temp. I have an analog thermometer on a suction cup in the front opposite corner, as far away from it as possible, and the temperature it registers is worth the money. I'll most likely be getting another one for my kids' aquariums as winter approaches to keep their fish friends warm.