Bluetooth microphone

Hello all, just read a great write up on adding right side steering wheel controls when upgrading radio.
The OP was fantastic about pics, p/n's and everything except the microphone part. I understand to sync bluetooth and have phone capabilities its important to have a mic in the system, anyone have any info on toyota p/n to factory microphone and how it integrates with system.
Im installing a 2012 non nav factory radio.