2.0,3.5mm Aux in,USB powered ,Class D amplifier, 50% higher efficiency,Max 2W / Ch,1 ... 20kHzSNR: >75 dbTHD: <5% @ 1 kHzDimensions: D55*W62*H62mm CablesStereo audio cable: Black, 1.5 m with 3.5 mm ... 1.5", 4ΩInput impedance: 10 kΩAudio input: Stereo 3.5 mm audio jackPower input: 5V over USB; optional 110V/ ... 220V power supply Cables Stereo audio cable: Black, 1.5 m with 3.5 mm ...