Altec Lansing inMotion iM5 Portable Audio System for iPod (White) Compatibility: iPod nano 1G; iPod mini; iPod 3G, 4G, 5G, 5.5G Highly efficient Class D amplifier delivers more than 24 hours of continuous playback with four AA batteries (not included) Superior MaxxBass technology for quality bass without a subwoofer Built in iPod docking station for data transfer and iPod recharging Compact design folds to close for convenient mobility--folds to 8.4 x 2.1 x 3.8 inches (WxDxH)