Two power sources - Longer operating time. Rechargeable lithium battery or USB charging. The rechargeable USB fan battery comes with a 2800 mAh 18650 lithium-ion battery for longer outdoor use (2.5-8 hours depending on speed). The battery requires approx. 3 hours to fully charge This USB desk fan is also powered by USB for indoor use such as PCs, laptops or power banks, providing more comfort. New version USB fan clip and table desk dual use. Improved version unique basic design. The USB fan clip can be placed on the desk or securely attached to your office desk, coffee table and headboard, with a strong clip that fits boards within 5 cm. Fitted with rubber feet to prevent damage or slipping. Suitable for office, home, dorm, pram, car or bed for extra coolness on hot days. Super silent and 720 degree rotation: we use the brushless motor for this fan, the brushless motor makes this fan very quiet when it is running. The USB fan quiet with quiet operation, you can sleep comfortably without disturbing the noise. Supports 360 degree horizontal and vertical rotation, adjust the direction of the wind with 360 up and down, left and right adjustment, you can enjoy the cool wind from all directions. 3 adjustable speed USB fan quiet: Our USB table fan is equipped with a single rock switch makes operation easy and flexible. 3 mode from breeze to strong wind, speed 1 is the lowest wind, speed 2 is the medium and speed 3 is maximum. (Use powerful brushless motor, maximum speed is up to 3500r/min, low noise up to 30-36db). Safe, compact, lightweight mini USB fan - 5 inch portable frame saves space on the desk, the USB mini fan with secure ABS mesh cover, the radiator grille is small enough and use soft PP blades, so you do not worry about finger hurting by accident, even safe for baby. Effectively protect against accidental injury.