The boxtech Aquarium Heater is a high-quality, durable heater that is perfect for keeping your fish tank warm. With a 300W output, this heater is powerful enough to keep a 55-80 gallon fish tank warm. The heater is made of heat-resistant milky quartz glass and has an UL-approved power cord. The controller is designed with an external temperature sensor so it can quickly sense the water temperature and make adjustments accordingly. The heater also features a Quartz Tube Safety Protection system to prevent electrical leakage and overheating.