2.0 speakers with usb, sd,fm, mp3 wire line control Used for notebook Power: USB Cable OEM&ROHS&CE 2.0 speakerswire line controlUsed for notebook,with usb, sd,fm, mp3Speaker unit: 1.5"*2Output: 3W*2 Impedance:4ohmFrequency response: 80Hz~20KhzS/N Ratio:≥80dBVoltage: USB DC 5VExternal lithium battery