The plug on the microphone cable and the socket used on the logic boards are a custom part for Apple. The extended plug is how power is supplied to the microphone.
No information is available on how to get the plugs or sockets.
There are two possible workarounds to get a longer cable. First, you could splice in an added length of cable to the PlainTalk Microphone. However, that voids the warranty. Another work around would be to use a different type of microphone from a different vendor. This may be a bit more costly than splicing the cable but, depending on the microphone used, you may receive a better quality signal.
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