Item Type: Sound Mixer Passive Material: Acrylic Input Impedance: 10KΩ to 47KΩ Output Impedance: 2.5KΩ to 10KΩ Gain: -12dB Maximum Interface: 3.5mm Sound Interface 1、Applications: Sound mixer for extended control of tuning, mixing instruments, CD players, tape players, computers, cell phones, tablets.  2、Plug And Play: Stereo mixer is small and portable, plug and play, no external power required. It is very convenient.  3、Control Knobs: Stereo mixer is a four way independent control knob, for each channel volume fine amplification, without interfering with each other.  4、Stereo Interface: Sound mixer is four in one out, all 5mm stereo input and output, can also be used as a 4 in 1 out stereo splitter, clockwise rotation to adjust the volume.  5、Premium Material: Stereo mixer is acrylic material, gold plated interface can effectively avoid poor contact to ensure stable signal transmission.