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The difference between the Bose® SoundDock® Series II and the Bose® SoundDock® Portable is that the SoundDock® Portable includes a rechargeable battery. This allows for the convenience of moving the system easily to a different room or location, while still delivering rich, detailed sound without requiring access to an electrical outlet. The SoundDock® Portable also includes a rotating dock to fold neatly inside of the main enclosure to protect it in transit. Both systems provide high quality, life-like audio and each include a remote control and 3.5 mm auxiliary audio input.