Kensington K33457US Charging Dock with Mini Battery Pack for iPhone and iPod, including iPhone 4 Compatibility: iPod mini; iPod nano 1G, 2G, 3G, 4G; iPod classic 1G, 2G, 4G, 5G, 5.5G, 6G; iPod touch 1G, 2G; iPhone 1G, 3G, 3GS, 4 Included rechargeable mini battery pack extends play time up to 30 hours of music, 6 hours of video, 3 hours of talk Dock simultaneously charges your iPhone or iPod and Mini Battery Pack Charges your iPhone or iPod even when in a case Includes detachable USB charging and syncing cable--charge via computer or wall outlet