Aquatop's Mantis Mini Aquarium Heater's compact design allows for versatile placement in small aquariums. Each unit has a built-in electronic thermostat preset to 77 degrees Fahrenheit for precise temperature-controlled accuracy of ±1.8 degrees Fahrenheit. When the target temperature of the heater has been achieved, the unit will shut down and stop heating the water. Constructed from a heat-resistant material, the Mantis Mini Heater will heat your aquarium water quickly and accurately, plus the included suction cups allow quick and easy installation.