The Dewei Submersible Aquarium Heater is a small, yet powerful heater that is perfect for keeping your fish tank warm. With a wide temperature range of 68 to 94 degrees Fahrenheit, this heater is perfect for keeping your fish comfortable at all times. The LED display design makes it easy to keep track of the temperature in your fish tank, while the external temperature controller makes it easy to adjust the temperature as needed. The over-temperature protection feature ensures that your fish tank stays safe and secure, while the 1 year warranty provides peace of mind.