Eliminate the traditional need of charger, charge your MP3 at anytime anywhere during day time using solar energy even when the MP3 is at work. Make the most of limitless free power of the sun. Ideal for outdoor enthusiasts, on the beach, in the hills or anywhere that you need a substitute for 'mains' power, allow you fully enjoy the freedom. A "must have" in today's hi-tech gadget world, save power and protect environment, keep you stay ahead of fashion Easily portable with handheld strap. Compact, cool looking like Zippo, high power, stylish and practical. Work for MP3 MP4 players or cell phones with 3.6V built-in rechargeable battery. Built-in USB 2.0 interface. LED indicator. Solar battery: 0.4 W. Output voltage: 5.1V.