Rechargeable 5" Battery Operated Swivel Fan by O2 Cool - Smart Power Technology: Built-in rechargeable batteries, AC adapter (included), Car Charger (not included), or use with 4 D cell batteries (not included). - LED lights show the power source being used. - Exclusive 5 fan blade offers quiet cooling. - Pivoting fan cage for the most effective cooling. - 40 hour battery life (typical use on low) + 3 hour rechargeable battery life (typical use on low).