The MA-202 adaptor cable allows you to connect an instrument and a microphone into the 1/4" input on your instrument amplifier. Just plug in your instrument and microphone and balance the volume using the normal volume controls on your guitar, bass, or keyboard. The special circuit will combine the signals without the problems found using a typical Y-cable. This keeps interaction between the instrument and microphone at an unnoticeable minimum and adjusts the volume to match what you would find with a typical single instrument. The included microphone adapter is used to connect the XLR output from a normal low impedance microphone into one of the one of the GA-101 adapter jacks. Package includes one GA-101 adapter cable and one MT-21 XLR microphone adapter.