When related to the photo voltaic panel, the fan can run; and may be used on my own via plugging into the computer's USB port. When connected to a solar panel, the style the fan works is dependent upon the sunlight. When the photo voltaic is irradiated to generate scorching air, the fan straight rotates to apply up warmth in time, ventilate, save the trouble of pulling wires, and it's and extra convenient. There is no rechargeable battery within the fan; if you wish the fan to work at night, you should utilize the flexibility pack. Specification: Solar panel chip: Polysilicon Solar panel power: 5W, 6V Panel size: 14/5 Mini fan: Size: 4 inches Power supply: USB plug, 5V USB cable length: 70cm/27 Material: Metal colour: black Package Contents: 1 x Solar Panel 1 x Fan Only the above equipment content, other merchandise are not included. Note: Light and assorted reveals can cause the color of the article within the photo a bit varied from the real thing. The measurement allowed error is +/- 1-3cm.