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. Compact design allows for versatile placement in small aquariums. Built-in electronic thermostat preset to 77 degrees Fahrenheit for precise temperature-controlled accuracy of ?1.8 degrees. Constructed from a heat-resistant material. Included suction cups allow quick and easy installation.