Aquarium Heater 300W with External Temp Controller & LED Display, Digital Thermometer, Auto Shut-Off, Overheat & Dry-Run Protection, UL Safety, Temp Sensor, for 40~50~55~60 Gallon Saltwater Freshwater

【Easy Temperature Control & Real-Time Display】When powered on, the LED screen flashes for 3 seconds showing the preset temperature. Press the external controller button to enter setting mode (68–94°F / 20–34°C) and cycle through your desired temperature. The setting saves automatically after 5 seconds and returns to real-time water temperature display. The red light turns on to heat when water temp drops 2°F (1°C) below set point, and heating stops with a blue light once target is reached. Press and hold the button to toggle Fahrenheit/Celsius.

【Comprehensive Safety Protection & Accurate Sensing】Our submersible aquarium heater has dual intelligent protection for safe, reliable use. When water temperature exceeds 98°F (35°C), the display flashes “E2” and heating stops to prevent overheating. If exposed above water, the screen flashes “E1” and heating stops to avoid dry burning. The built-in high-precision sensor provides ±1°C (±2°F) accuracy, helping you monitor tank conditions. With a smart circuit protector, it ensures enhanced safety and durability.

【Built-in Sensor & Free Thermometer】This heater includes a built-in sensor plus a free thermometer for more accurate temperature control than one alone. If one fails, the other keeps working to ensure safety. It auto shuts off at the set temperature, saving energy and maintaining stability. Features a protective guard and durable ABS housing to prevent fish contact. Easy to install—just submerge and fix with suction cups. Suitable for saltwater, freshwater, turtle, betta tanks, small ponds, and more.

【Efficient Heating & Safe External Controller】Inside, high-quality nickel-chromium wire is evenly wrapped to quickly disperse heat over a larger area, improving heating efficiency. The external adjustable controller reduces the risk of water entering and damaging the heater, extending its lifespan. You can safely adjust the temperature without reaching into the water. The digital display allows you to clearly monitor real-time water temperature at any time.

【Safety Precautions for Use】For safe use, always fully submerge the heater before plugging in to avoid dry burning. Place it near water flow for even heating, and firmly fix it with included suction cups to prevent movement. Avoid touching while in use or right after unplugging to prevent burns. Always unplug during water changes and keep the cord and plug dry and away from water. Regularly monitor water temperature with a thermometer. If damaged or malfunctioning, stop using immediately and replace.

【Worry-Free Purchase with 180-Day Warranty】As a trusted brand seller, we are committed to providing high-quality submersible aquarium heaters and stand behind every purchase. We offer a 180-day warranty from the date of purchase. If you encounter any issues during use, please feel free to contact us, and we will be dedicated to resolving your concerns.