How to use:1-IN-2-OUT: Connecting 1 audio source (like active microphone or MIDI key board) to I/O port and 2 audio receiver device (like recorder / microphone mixer) to A/B ports.A/B selector: select audio input or output from A or B channel.MIX switch function: set the KN102 work at Mixer mode or A/B selector.Notice:1. In normal mode, A or B channel will input or output independently. While in mixer mode, A and B channel will combined input or output at same time(A/B selector will not work).2. When A and B channel input at the same time, two input audio device must be the same type otherwise they will interfere each other.Parameters:Connector: 2*Female XLR and 1*Male XLR (2-IN-1-OUT)Material: aluminumColor: blackDimensions: (L)58mm*(W)88mm*(H)30mmNet Weight: 200gPacking List:1 * XLR Audio Switcher