The mixer is equipped with, input gain and high and low bass adjustment, the built-in 48V phantom power supply is suitable for direct power supply of condenser microphones, high-definition headset output port, MP3 player, bluetooth receiver, and a connected PC sound card. The mixer is small and light, and can be directly connected to the USB port of the PC for power supply. No additional power supply is required. It can be operated by connecting the computer to the power supply through the USB, eliminating the trouble of using an external adapter. Item type: Sound Mixing Console ower: mobile power or USB Channel: 4 Totai Harmonic Distortion: 0.1% Frequency Response: 20Hz-20KHz/±0.5dB S Ratio: 80dB MAX Outputs: 4V/MAX MIC Impedance: 2.4ohm Mono Impedance: 11 Stereo Impedance: 100 Parametric EQ High: 12KHz/15dB Parametric EQ Low: 80Hz/±15dB Colour:black Material:ABS Size:15x18x5.5cm Package Contents: 3 x audio mixer 3 x USB wiring 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.