Fluval M 50 Watt Submersible Aquarium Heater
Fluval P50 50 Watt Submersible Aquarium Heater - Up to 15 Gallons
Aquatop Submersible Aquarium Heater 50 Watt
Fluval T50, 50 Watt Fully Electronic Aquarium Heater
Aquatop Submersible Aquarium Heater 75 Watt