SMSL Audio Black SD-793II Headphone amplifier The whole machine power <8W headphone output power: 65mWat16 ??130mWat32; headphone output distortion: 0.01%THD+Nat100mW/32 The machine volume: 128 x 77 x 35mm ( including protruding parts) weight: 0.5Kg ( actual weight carriage outside packing structure. ) configuration: SD-793II host 1, manual 1 ( in English ), universal with Japanese PSE power 1. voltage: 100-240ACV universal power supply