Newa Therm Mini K 20W, small completely submersible aquarium heaters which are perfect for the nano aquarium enthusiast. These unbreakable heaters are highly efficient using just 20 Watts. The thermal-protector prevents against damage caused by thermal shock or dry use. If the heater runs dry, or is removed from the water while switched on the heater switches off. Once the heater has cooled, or when it is re-immersed it switches on again. Features: Thermal protector. Maintains water temperature at 25?C +-1? C. The thermostat needs no regulation. A red light indicates when the heater is running. Supplied with suction cups.