Rust and Corrosion Resistance: This aquarium heater is made of high quality stainless steel material, which is sturdy, rust and corrosion resistant. Double-layer waterproof protection design---This aquarium heater features double-layer waterproof protection and fully submersible design, can accurately maintain the set temperature and will not cause short circuit. Thermostatic Design: This aquarium heater adopts double metal silver-plated contact temperature control and internal fixed temperature adjustment process, with strong temperature sensitivity and small temperature error. Wide Temperature Range and Large Depth: This aquarium heater can be adjusted from 18 to 34 degrees, its maximum submersion depth is 120cm, suitable for use in fresh water. With Strong Suction Cup: This aquarium heater with strong suction cup can firmly fix the heater on the tank and keep stable for a long time.