The Betta Choice Premium Submersible Aquarium heater ensures reliable and consistent water temperature for your aquarium. It comes complete with a protective guard to prevent damage and to ensure the safety of your fish. The temperature can be adjusted between 20 - 34 deg C. The heater is fully submersible and can be controlled manually. Mains power indicator. Waterproof double seal material for safety. Aquarium heater/thermostat 50w - for aquariums upto 50ltrs