Feature: 1. Sturdy Shell: The Aquarium heater is made from ABS protective cover, can withstand high temperatures without softening or deforming, and boasting long lasting durability. 2. Digital Display Controller: The heater features a dual display external controller that shows the current temperature and set temperature, precise up to 0.1 Celsius degrees. 3. Efficient Heating: The fish tank heater features U shaped ceramic heating sheet for fast heating but no light emission, significantly improving heating efficiency. 4. Leaving Water Automatically Stop System: The submersible fish tank heater is designed with a leaving water power off function to prevent drying out and a possible fire hazard. 5. Enhanced Safety: The freshwater saltwater heater is equipped with dual relay to prevent potential damage caused by single relay failure, ensuring double safety. Specification: Item Type: Aquarium Heater Usage: Maintain constant temperature in fish tank for easy tropical fish breeding, ideal for fish to survive winter Material: Ceramic Heating Sheet, ABS Safety Protective Cover. Package List: 1 x Heater (With External Controller)1 x Fixed box1 x Instruction Manual