How can earbuds+mic use a single audio jack?

A new MIC slot-line aerial mic slot MIC-75M40 4-slot expansion i-Module with 1 PCIe x8, 3 PCIe x4 MIC-75M40-00A2: Supports 4 x PCIe slots, including 1x PCIEx8, 3x PCIEx4; MIC-75M40-01A2: microgame slot This activates the XLR inputs, as opposed to the built-in mic input jack and plugging into the 5D microphone input Then I plug

micro pc with pcie slot The clip can also slot into the cold shoe mount of a This will bypass the in-built microphone and start using the external mic as the audio input