USB Powered Tank Heater Safe operation with a 5V/2A USB power supply. No risk of electrocution to fish. Power adapter (5V/2A) or power bank is not included. Overheating Protection and Poweroff Memory Function If water temperature exceeds the set maximum, the heater stops automatically. It remembers your temperature setting, and when power is restored after an outage, it resumes with the last setting. Mini Aquarium Heater Compact design at 5 cm (1.97 inches) in length, allowing it to take up very little space and be easy to hide in the tank. Temperature range for the English Celsius model is 18C34C. Please choose according to your needs. Precise Temperature Display Smart inverter technology with a builtin control chip maintains a stable temperature. Provides more precise control than knobbased heaters, with an easytoread temperature display. Use scenarios Nano or desktop freshwater aquariums where space is limited and a discreet heater is preferred. Small betta tanks or compact tropical setups that benefit from reliable USBpowered heating. Planted or decorative tanks where the heater can be tucked behind plants or decorations for a clean, unobtrusive installation.