nitekillerz

i searched and couldn't find an answer. I have a 2009 scion tc RS 5.0. when i bought it though(used) there was a stock looking switch tracing back to the stock radio that has hang up sign and two arrows up and down(guessing that its for volume) when i press and hold the call button i get some beeps but im just wondering wtf is it used for? does my scion have a factory mic? and where? if not then how would i use that function?(with the mic on my phone)

anybody know what its use for?

tCjosh

iTrader: (8)

the tC's don't have a factory mic so it might have been something the previous owner installed...