Make installation of -6AN lines to your factory hard lines a simple task. This innovative two-piece fitting clips together on the VW/Audi 5/16"" factory hard line and threads together to create a tight fit. Each fitting comes complete with a Viton o-ring that can withstand corrosive fuels, such as ethanol, to ensure a leak-free connection. Manufactured out of 6061 aircraft grade aluminum, the part is anodized in black for a sleek but discrete look.