Heater: This aquarium heater must be 100% submerged in water, ideal for small glass or acrylic desktop aquariums up to 1-6 gallons, not suitable for tanks under 1 gallon. Quick and easy installation: Mimic the original ecological environment for your tropical fish. Aquarium heater automatic temperature control 78℉, no need to set the temperature, easy to use. How it works: Plug in, the red light turns on, the heater starts working until the water temperature reaches 78°F and the red light turns off, then the green light turns on, the heater stops working and maintains a constant temperature of 78°F. Accuracy: ±3°F. High quality: Aquarium heater made of high-quality quartz glass, double sealing material, advanced design, ensures safe operation. Bnzaq aquarium heaters are made of BPA-free plastic, safe for fish without producing any toxic substances. Low consumption: This aquarium heater has low power consumption of 25W, stable performance and high reliability. And with two strong rubber suction cups, it is firmly attached and does not fall off easily.