Aquatic 5 Watt Flat Heaters provide warmth for small tropical fish and are designed for glass or acrylic desktop aquariums up to 2.5 gallons. They are completely submersible, easy to install and efficiently warm aquarium water. Suctions cups are included so you can mount the heater to the bottom or side wall of the aquarium. Be sure to choose the appropriate size for your aquarium. Do not operate or leave product plugged in when it is outside of water. Aqueon products offers a wide range of items so that you can build and maintain a healthy aquatic environment. All the essentials from fish tanks, filters, lighting, food, care, and other supplies that your pet fish needs. We make it easy for you to get your first aquarium and to grow in the hobby as you become more of a fish expert with every step you take and every new thing you learn. For those seasoned hobbyists, we are committed to aquarium product innovation so that we continue to offer products that get you excited. With the Aqueon brand, it's all about the fish.