O2COOl 10&rdquo; Battery Operated Fan - Portable with AC Adapter & USB Charging Port, Rechargeable for Emergencies, Camping & Travel Use Smart Power technology - Fan automatically selects lowest cost power option. Power sources: Plug-in with the AC or DC adapters (included), use 8 D-Cell batteries (not included), or use built-in rechargeable batteries. Powerful 2 speed 10-inch blade. USB Power Port for charging your cell phone or other mobile devices. Convenient flip-up handle.