🐡【Over-temperature Protection and Anti-dry Burning Function】 Automatic constant temperature function, Temperature Range is 68℉- 93℉. When water temperature is 1°F higher than the set temperature, the aquarium heater will automatically stop heating; when water temperature is 1°F lower than the set temperature, fish tank heater will restart heating. When aquarium fish tank heater leaves water, the heating rod will automatically cut off the power to stop heating, and the display will display "E1". 🐡【Explosion-proof Silicon Carbide Aquarium Heater】The adjustable aquarium fish tank water heater is made of explosion-proof quartz glass material and a high-temperature resistant nickel-chromium heating wire with silicon carbide heat conduction. The silicon carbide material can make the heat conduction very stable and dissipate heat evenly. And the stronger black shell is a high temperature resistant ABS material which protect the fish, your aquatic organisms and you from scalding. 🐡【30% Energy Saving and Fast Heat Conduction】This 200W aquarium heater has two built-in silicon carbide heating tubes. The silicon carbide material is filled between the heating wire and the glass tube. Silicon carbide is a conductor with fast heat conduction and strong stability, which can quickly transfer heat and then dissipate it. Save heating time and energy. Before enabling the heating rod, you need to allow the water to flow so that the heat circulates evenly in the fish tank.