O2COOL 10-Inch Portable Smart Power Fan with AC Adapter & USB Charging Port Nullify 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, stable base with stabilizing feet Tilts for directional air flow, compact design makes it great for travel; east to carry and store