USB SD Speaker, 1.USB , LINE IN, TWO POWER SUPPLY(USB+4xAAA BATTERIES) LI-ION. 2.Competitive price&High quality USD SD SPEAKER 1.Abundant supply and ... Especially designed driver unit ,with beautiful sound.3.Using computer USB port instead of power adapter for power,it's small ... 2 Inch*2 4Ω Frequency Response: 150Hz-20 KHz USB Voltage: 5V (500mA) USB Special Cable: 1000mm Signal Cable: 1000mm Φ3.5mm ...