ETONG Hand-held Mini Fan Portable Electric-Powered Cooler 3 Speeds USB Fan Rechargeable Personal fan with 18650 Rechargeable Battery (Black) Dual Power Sources: The rechargeable fan adopts Li-ion 18650 battery (included); through USB conncection it can be powered and charged by your computer/laptop, and other 5V-output USB chargers. Adjustable 3 speeds: The portable fan speed can be adjusted among low, medium, high according to your demands. High energy efficiency: when the battery is charged full, the fan can generally be used 10 hours at the lowest speed, 2 hours at the highest speed. Note: Please remove the insulation sheet of the battery before use. With a mini mirror in the center of the fan, can be used to make up while breath the fresh air. Powered by 2*18650 battrey (included) or USB: ideal for travelling, jogging or sun bathing etc.