Key Features Provides accurate and stable heating for your aquarium Fully submersible. Provided with suckers to attach to the side of the tank. It is recommend to install diagonally On/Off LED light that indicates if the heater is operating Easy to control with the top located button. Simply adjust for required temperature 1 Year Manufacturer Guarantee Interpet Aquatherm Aquarium Heaters are an accurate tool to ensure the correct heating of your tropical fish tank water To ensure a Tropical tank thrives, maintaining the correct temperature is a key component of aquarium care. The Interpet Aquatherm Aquarium Heaters are slim line submersible heaters that are easy to use and control. Each heater has a convenient top located control knob that is easy to turn, and in doing so the value shows up on the glass front to clearly display the desired temperature. The front of each heater has a clear to see On/Off LED light that indicates the heater is working. Each tube is made of high quality