1. The mixer is equipped with, input gain and high and low pitch adjustment. The built-in 48V phantom power supply is suitable for direct power supply of condenser microphone, high-definition headset output port, MP3 player, Bluetooth receiver, and connected PC sound card. 2. The mixer is small and light, and can be directly connected to the USB port of the PC for power supply. No additional power is required. It can be connected to the computer for power supply through USB, saving the of using an external adapter 3. You can also use a mobile power supply or USB AC/DC adapter to power it. 4. This mixer is a multi-purpose 4-channel mixer with sound card, which can the 's needs music production, online live , karaoke cover, etc 5. Mini portable, easy to operate Model: A4 Totai Harmonic Distortion:less than 0.1% Frequency Response:20Hz~20KHz/0.5dB S : -80dB MAX Outputs:4V/MAX Input/Output impedance: MIC:2.4Kohm :11Kohm Stereo:100Kohm Parametric EQ: HI:12KHz15dB LOW:80Hz/15dB Product size: 180 150mm Function: 1,2 channel signal input channel stereo input 2,One main channel output,one AUX output and feed back 3, channel for recording output and monitor 4,Low-noise,high-precision microphone preamplifier with perfect sound 5,Balanced XLR microphone input and balanced inputs,3-band channel EQ 6,48V DC phantom power will responsible for connect with condenser mic,and power supply for input port 7,Port for eqrphone monitor 8,Precision logarithmic double 10 LED level display 9,MP3 module,USB interface,and display 10,Built-in switching power supply is flexible(AC100-240V AC),low power consumption Plug Type :EU Plug,it appliesto Indonesia, , , , and so on. Colour:black Material:ABS Package Contents: 1 x 1 x USB power cord 1 cord plug 1 x English manual Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.