1. The fan starts to run when it is plugged into the solar panel, and it can also be powered from other USB devices such as mobile supplies, computers, etc.2. When connected to a solar panel, the operation of the fan depends on the sunlight.3. When the is strong, the fan will run quickly. When the is not strong enough, the fan may run slowly or even fail to work.4. There is no rechargeable battery in the fan. If you need the fan to work at night, you can use an external battery5. Portable, small size, easy to carry. No battery, quiet and green energy, good for the environment: 5W 5VMaximum : 5 (W)Working current: 1 (A)Working voltage: 5 (V)System voltage: 5 (V)Open circuit voltage: 5 (V)Short circuit current: 2 (A)Reference weight: 02 (KG)Panel size: 145x145x25MMSize: 4 inches supply: 5v USB cable cable length: 12MMaterial:metalcolour:blackPackage Contents:1 * 5W Solar Panel1 * fanOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.