The design simulates the appearance of mobile phone It is very light to carry Connect Multi-Audio Terminal Device:CD.MD.MP3.Notebook , etc 2 channel output and good sound quality It can use AAA battery or get power from USB of computer. that can save power consumption when enjoying music. Power: 1W*2 Dynamic Range: 45Hz-12kHz Input Voltage:5v S/N: 65dB Audio Line-in jack: 3.5mm Battery: 3xAAA