Microphone for phone calls. Be glad you didn't have to install it yourself; that seems to be an aftermarket thing and they're a pain to install, I did it just yesterday
Honestly don't get why the last person would add this, I find it easier to just use the speaker microphone & a phone holder that people use for maps and stuff
Yea it's totally for hands free calling, I figured it wasn't something to be afraid of when I first found it because it would be a ridiculously big big. Still a funny thing to find randomly, and remember don't believe anything any 3 letter agency ever says about me