Precise, compact USB aquarium heater designed for small tanks — digital temperature control, lowvoltage USB power, and builtin safety features. Key benefits Accurate temperature control: Smart inverter technology and a builtin chip maintain a steady temperature more precisely than traditional knobcontrolled heaters. The clear digital display makes it easy to read the set temperature. Lowvoltage USB power for safer operation: Runs on 5V/2A USB power (adapter or power bank required, not included), reducing electrical risk compared with highervoltage units. Small, discreet design: At just 5 cm (1.97 in) long, the heater takes up minimal space and is easy to hide inside the tank. Features and specifications Temperature range (English Celsius model): 18°C–34°C. Power supply: 5V/2A USB (use a 5V/2A power adapter or a 5V/2A power bank; both sold separately). Display: Digital temperature readout for quick, accurate monitoring. Control: Smart inverter chip provides stable temperature regulation — more precise than manual knob controls. Size: Miniature form factor (5 cm / 1.97 in) suitable for small aquariums and tight spaces. Safety and reliability Overheating protection: The heater stops operating if water temperature exceeds the maximum safe range to help protect aquatic life. Poweroff memory: If power is interrupted, the heater retains its last temperature setting and resumes that setting when power returns. Lowvoltage operation reduces electrical exposure inside the tank; follow installation guidelines and use only the recommended 5V/2A power source. Practical applications Small freshwater aquarium for tropical fish where steady temperatures are essential for health and activity. Shrimp or betta tanks where compact size and minimal equipment visibility matter. Portable or temporary setups powered by a 5V/2A power bank during travel, exhibits, or maintenance (use a compatible 5V/2A power bank). What this solves Eliminates temperature swings common with knobcontrolled heaters by offering precise, chipbased regulation. Reduces space and visual clutter in small tanks due to its mini size. Provides straightforward, lowvoltage power options for safer, flexible placement. Installation and use notes Use only a 5V/2A USB power adapter or 5V/2A power bank (not included). Confirm the heater's temperature range meets your aquarium's needs (English Celsius model: 18°C–34°C). Place the heater where water flow will allow even temperature distribution and follow standard aquarium safety and maintenance practices.