Compact, lightweight and lid-lifting design Elegant shape with folding bracket, convenient to carry on your travel High quality dynamic sound With volume control and power on / off to choose Multi-function, ideal for Portable IPOD/ PC/ MP3/ CD/ MD/ mobile phone etc. Power source: USB BUS-power / AC adapter 6V 350mA / Battery: AAA x4 Output: 2W*2 Frequency Response: 20Hz-20KHz Output impedance: 4 Ohm Power: 3V-6V DC: 3.5mm With adapter