The Cat-Back systems are designed as direct replacements for the original exhaust, offering improved sound and aesthetics. Multiple configurations are available, allowing the owner to select the desired increase in exhaust volume or a more aggressive tone. Manufactured from 304L aircraft grade stainless steel, these systems are built to withstand harsh conditions. All products are made in the UK and distributed to over 90 countries. - Direct replacement for the original exhaust system - Available in multiple configurations for sound and tone customization - Constructed from 304L aircraft grade stainless steel - Made in the UK and distributed worldwide Specifications: - Pipe Diameter: 57.15 - Installation Time: 2 to 3 hours (including removal of OE system) - Race Product: No - EMarked: No Kit comes with: - Front Link Pipe Assembly - MSAU176 - RH Centre Section Non-Resonated - MSAU177REP - LH Centre Section Non-Resonated - MSAU178REP - LH Rear Silencer - MSAU270 - RH Rear Silencer - MSAU271 - Brace Bar - MSAU314 - Jet 100 Cerakote Black Trims - MSTIP273 Vehicle Compatibility: - 2003-2005 Audi S4 4.2 V8 quattro B6 Saloon/Sedan, Avant, Cabriolet