Heater: This aquarium heater should be 100% submerged in water, ideal for small glass or acrylic desktop aquariums up to 1-6 gallons, not suitable for tank less than 1 gallon. Quick and Easy Installation: Imitating the original ecological environment for your tropical fish., Aquarium heater automatic temperature control 78℉, No need to adjust the temperature, easy to use. How it works: Plug in, the red light will turn on, the heater will start working until the water temperature reaches 78°F and the red light will turn off, then the green light will turn on, the heater will stop working and keep a constant temperature 78°F. Accuracy：±3°F High Quality: Aquarium heater made of high quality quartz glass, double seal material, advanced design, ensures safe operation. Aquarium heaters are made of BPA-free plastic, safe for fish without any toxic substances producing Low Consumption: This aquarium heater has low power consumption of 25W, stable performance and high reliability. And with two