You can press and hold the button next to the controller for 2-3 seconds to switch. It has a built-in temperature control system of Fahrenheit and Celsius(Temp range: 63-94℉/17-34℃). 🐠【Rapid Heating and Two Temperature Control System】300W aquarium heater is sutable for 40-75 gallon fish tank and made of the most stable nickel-chromium heating wire, which can quickly and stably conduct heat to the surroundings.12 Month Warranty and 24 Hour Professional After-sales Service. ★【SATISFACTION GUARANTEED】Gain the confidence to go hard with us! Our Aquarium Heater is built with durability in mind and safety for every design, In the remote possibility that you’re not satisfied with our product, just contact us, and we will gladly give you a new Aquarium Heater replacement.

★【Note】:this heater is 100% submersible use only, during its heating time, heater must be 100% submerged into the water.

★ Touch button, cyclic adjust temperature, easy to use and Safety.

★ Automatic constant temperature function, when water temperature reaches to specified temperature value, heater will automatically stop heating, when water temperature is lower than the set temperature, heater will automatically start heating.

Upgrade function: The heater will auto shut off when it is out of water and turn normal when fully in water again.

★ Temperature range: 59☏~94☏, display Fahrenheit ☏, this heater is designed for1~10 gallons tank.

Modern betta fish tank with filter