The Finnex Compact Electronic Titanium Heaters maintain water temperature within +/-2ºF of the set value providing a safe, healthy, and stable temperature for your tank. The titanium tubes are corrosion resistant which makes them virtually unbreakable for both saltwater and freshwater aquariums. These ultra-fast heating tubes are easy to hide as they are compact in size and also include a precise electronic control with a hang-on hook. There is also a LED Heating indicator to let users know when the heater is functioning.