The Sunleaves DigiTherm HydroHeater is a simple and effective way to maintain water temperatures in reservoirs and other water receptacles. It features an easy-to-read display, a power indicator light, and an auto shutoff function that activates if the temperature exceeds 92F or the heating tube is no longer submerged in water. Six different wattage varieties of the Sunleaves DigiTherm HydroHeater are available, all of which are protected by a one-year warranty. This 200W unit is recommended for 39-52 gallon reservoirs.