Four condenser microphones work at the same time, the volume of the four microphones is independently adjustable, and the mixed total output is connected to the microphone input end of the sound card, and it comes with 2 times amplification. The 3.5mm interface comes with a bias voltage that can be connected to common electret microphones, condenser microphones, etc. 5V power supply, you can use computer USB or mobile phone charging head to supply power Using a rail-to-rail operational amplifier, the sound is beautiful and dynamic. Color: black Material: metal Package Contents: 2 x Audio Mixer 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.