Thanks for the info. I do know what it's for, I just had it installed last night. This thing is great.In case it was a serious question, you pull it forward an in a second or two you hear a beep. Then you just speak one of a few commands such as "radio" and the MCS will change modes. Pushing back will cancel the voice request.
You can also use it to pick up (pull forward) or hang up (push back) the phone when it rings.