Designed specifically for the new S4 Hotchkis Sport Sway Bar Set incorporates a 24mm tubular 2 position adjustable rear along with a 35mm tubular front. Polyurethane bushings and bushing brackets are also included along with 90-degree zerk fittings for easy lubrication. The set does not include a reinforcement bracket system which is not necessary for this application. Keep in mind that the stock S4 rear bar is a solid 20mm bar on two solid bushing towers. The biggest improvement will be felt through the steering as maneuvering takes much less steering input with greater response. While rounding tight or long corners the S4 feels as though it has more tire pressure on the outside tires and really stands on the outside rear exiting a corner. The new S4 which is a lot of fun in stock form just got more exciting with the addition of Hotchkis Sport Sway Bars! Rate increase over stock. Front: +60%Rear: +145% 215% Fits B6 and B7 platforms Sport Sway Bar Set; 1 3/8 in. Dia. Front; 15/16 in. Dia. Rear; 2004-2008 Audi B6/B7 S4