Just wind this dynamo light for one minute and get up to 30 minutes of light. The 3 LEDs will give a lifetime of super bright white light. Use the three-LED level for maximum brightness or the one-LED level for maximum charge length. Ideal emergency light for your glovebox, boat or home. The durable ABS body has built-in grips for comfortable winding and use. 5.5"x2"x2".