Aqua 2210 Premium Submersible Aquarium Quartz Glass Heater 300 Watt with Free Digital Thermometer - 55 Gallon CONSTANT AND ACCURATE WATER TEMPERATURE: Our Bimetallic Strip Heating Sensor controls the on/off function, ensuring accurate and consistent water temperatures in your fish tank (all fish welcome; including turtle, betta fish and goldfish). This is a critical component that prevents overheating and wide swings in water temperature, which ensures the health and well being of your aquatic friends. QUALITY DESIGN AND RELIABLE CONSTRUCTION: Our 300w heaters are made from high quality quartz glass that ensures no water leakage or malfunctions. The tube also distributes the heat in an effective manner and is never hot to the touch when submerged - the heating tube won't harm the fish should they touch it so no need for a bulky heat guard. A simple design that uses quality components means your have purchased a reliable long lasting heater. EASE OF USE: Our heaters have an easily accessible and adjustable dial at the top for regulating the fishtank water temperate; markings are in both F and C (no conversion required). A detailed user guide will be mailed out that outlines how to get the best results, including how the heater and thermostat can be used in conjunction with your water pump, to provide a "climate controlled aquarium". EFFECTIVE WITH DIFFERENT SIZED FISH TANKS: A single heater will successfully regulate the preset temperature of a 55 gallon saltwater or freshwater fish tank. Customers have also used our heater for 10 gallon, 15 gallon, 20 gallon and 50 gallon tanks. Voltage/freq: 110-120volt/60hertz. WARRANTY: Buy with ZERO risk. You have 90 days to get a complete refund, no questions asked and no need to send the product back to us. You also get a full year end-to-end guarantee on both the heater and thermostat. Order Now while stocks last!