It's a standard "V" belt, tho not so standard in the mounting of it as you will have to access the mounting bolts from the top and underneath the car to allow the alt to swing the put the new belt on.
Since it starts with POR, it will automatically begin at $100 at your local FLAPS, so why don't you ask for a VW 411 alternator belt.....it will only cost about $15 then.
Oh PS: If the alternator is locked up and you have to change it....get a good supply of bandages and make sure your SO and kids (if you have one/some) are not nearby to hear the language you will use when you try to change it.
Thanks Mike
"READ THE MANUAL"
AND PSS....to get your "Knowledge is Power" to come out the way you want...when you isssue the command for color, size, etc and hit the button, you must also click "close all tags"....This is not in the Haynes Manual