Perfect for both fresh and saltwater tanks, Aquatop’s-D2HT-450 watt digital heater includes a dual digital display that shows current water temperature and desired water temperature. This advanced and versatile heater is capable of heating aquariums up to 180-gallon and will give an accurate temperature within +/- degrees of desired setting. Equipped with a highly accurate temperature sensor, The D2HT-450 also includes automatic over-heating protection. If the temperature rises above 93-degree f, the heater will automatically shutdown.