50 Watt Aquatopia Hydrotherm Aquarium Heater is suitable for aquariums 25 to 50 litres. The Aquatopia heater is suitable for fresh and marine water aquariums. This fully submersible heater has a shatter-proof design. It comes with a clamp and suction caps, so it is easy to fix to the side of your fish tank. Set the heat you want and then the thermostatically controlled heater will keep your water at the temperature you choose. About the Aquatopia Hydrotherm Heater: 50 Watt Suitable for tanks 25 to 50 litres For fresh water aquariums and fish tanks Fully submersible (waterproof) Shatter-proff design Presets at 24 degrees Comes with clamp and 2 suction caps Energy efficient Low maintenance