Tetra HT Submersible Heater 100 Watts, For 10 to 30 Gallon Aquariums, UL Listed | Meijer
Amazon.com: Submersible Aquarium Heater, 300 Watt Adjustable Aquarium Heater,Adjustable Fish Tahk Heater,Tank Heater for 55 Gallon,with 2 Suction Cups,Free Fish Tank Temperature Sticker(40-60 Gallon) : Pet Supplies
Amazon.com: DaToo Mini Aquarium Heater 25W Small Fish Tank Heater 25 Watt with Free Thermometer Sticker : Pet Supplies
Amazon.com : Orlushy Submersible Aquarium Heater,150W Adjustable Fish Tahk Heater with 2 Suction Cups Free Thermometer Suitable for Marine Saltwater and Freshwater : Pet Supplies
Aqueon Adjustable PRO Aquarium Heater Up To 55 Gallon 150 Watts | eBay