The GENUINE part, in the car manufacturer's box, as sold by the new car dealer.Fits many VW/Audi models may even work for engines not listed in fitment. Most engines have some sort of oil galley plug, this is where the oil passages get machined at the factory then plugged to create the oil passage.
Some engines have one of these located behind the flywheel above the rear main seal. So make sure you know where the oil is leaking from. It could be from this plug and not your rear main seal. I would recommend buying a couple of these when ever removing the flywheel just in case it happens to be leaking.