1. DC 5V power supply port

2. 2, 3, 4, and 5 are single channel audio input ports from 1 to 4 channels

3.6 Adjust the volume of each channel and mix the total output port

4.7, 8, 9, and 10 are 1 to 4 audio input volume adjustment potentiometers. 5.11 is the power indicator light.