Montego II with s/pdif

[samuknow]

I just got a freebe from someone I built a computer for. He bought a SB live and gave me his Turtle Beach Montego II card. There is a daughter card that came with it. It has a s/pdif RCA connector on it. What exactly is this. I did a seach and read that it is a digital out. But how do I or can I use it?

Any one have this thing?