Specification: The fan starts to operate when plugged to the solar panel and it can also get power from other USB devices, such as power bank, computer, etc.Portable, small size, easy to carry around. No batteries needed, super silent and green energy, environmental protection.There is no rechargeable battery in the fan. If you need the fan to work at night, you can use the power pack.When connected to a solar panel, the way the fan works depends on the sunlight. When the sunlight is strong, the fan works quickly.Great combination, suitable for greenhouses, dog house, trailers, RV and so on. Also can be used for charging mobile phones. Specification: Condition: 100% Brand New Item Type: Solar Panel Material: Iron Color: As shown in the picture Solar Panel Size: Approx. 14.5x14.5cm / 5.7x5.7in Cooling Fan Size: Approx. 13.5x15cm / 5.3x5.9in Weight: Approx.353g/12.5oz Solar Panel Power: 5W, 6V Power Supply: USB plug 5v Application: Suitable for greenhouses, dog house, trailers, RV and so on