Review on 🐠 Zacro 100W Submersible Digital Display Mini Fish Tank Heater with Intelligent LED Temperature Display and External Controller, Suitable for 10-20 Gallon Aquariums by Robert Rick

Good product at a good price. I use for factory tank heaters and they work great for that. The water shortage auto shut off feature is really very good as I broke the others because I forgot to turn them off while I was feeding the plants. I also like the remote control feature so I don't have to pull it out or buy a separate controller to change the tank temperature. Good product. I will buy more if needed. They keep my 5 gallon and 20 gallon at the right temperature and get there relatively quickly. However, for a large tank, a larger one is better.