This billet port cover closes the port of the rear breather on the turbocharger This is perfect for installing a catch can system. Will fit all 2.5L TFSI like RS3 and TT RS Made of 6061 aircraft aluminum and red coated. Manufacturer Information about the manufacturer BAR-TEK BAR-TEK Motorsport GmbH Im Rauschen Auel 3, 51491 Overath-Brombach, Germany info@bar-tek.com