Exquisite appearance, small and exquisite. Two-way mixed input: stereo RCA lotus mouth or small three 3.5mm mouth, which can be input and mixed at the same time. External AC transformer: Make the sound more stable, with less bottom noise and stable sound. The function is portable, the interface supports 6.35mm and 3.5mm at the same time. Up to 8 earphones or audio equipment can be plugged in at the same time. 4 independent control knobs, gain up to 20db. Input interface: stereo 3.5mm/TRS interface/stereo RCA interface Input impedance: 22k ohm Input signal: 22db Output impedance: 16 ohms Maximum gain: 19db Coinage first: Greater than 98db Power supply: DC12-18V, external power adapter Colour:Blue Material:Metal Package Contents: 1 x Headphone Amplifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.