We design and manufacture an external power battery for iPod. It has its own advantages: 1. External Power Bank:can power & charge iPod any time and wherever you want; can extend iPod more than 14 hours of working time. Plus with iPod built-in battery 8 hours working time, the total is more than 22 hours for iPod working time. Very interesting! 2. Data transmission: can transmit data of iPod to PC computer via its Mini-B interface(replace of iPod expensive?T? type <USB2.0+FireWire cable >data transmission cable) 3. Pocket Leather Case design adds protection function and convenient portability(replace of iPod original leather case), very smart design. 4. Can offer 5V output power to charge mobile phones(optional function). 5. Available for iPod four Gens including 40G,30G,20G,15G...and Mini iPod product.