\u2605TWO POWER SOURCES- Longer Operating Time. Rechargeable battery or USB charging. The rechargeable usb fan comes with a 2800mAh rechargeable battery for longer using outdoors (2.5-8 hours depending on different speed). The battery need about 3 hours for full charging. The desk fan with usb also powered by USB for indoors such as PCs, laptops or power banks, providing more convenience.\n\u2605NEW VERSION CLIP ON FAN & USB DESK FAN DUAL USE. Enhanced version unique base design,the usb fans desk can be placed on the desktop, or clipped to your office desk, and headboard securely, with a strong clip that fits boards within 5cm. The usb fans equip with rubber pads so it would not damage your furniture, and will not slip.\n\u2605SUPER SILENT & 720 DEGREE ROTATION- We use the brushless motor for this mini fan usb, the brushless motor make this fan very quiet when it's running. The usb fan with quiet operation, you can sleep comfortably without the noise disturbs you. Support 360.