Xforce Twin 2.5" to 3" Cat-Back System with Varex Muffler, 304 Stainless SteelXforce Twin 2. 5" to 3" Cat Back System with Varex Muffler, 304 Stainless Steel Silenziatore Varex in acciaio inox 304. Upgrade your Audi 8V RS3 Sedans exhaust system with the Xforce Varex Cat Back Exhaust System . This high performance exhaust system is designed to deliver an aggressive exhaust note while improving horsepower and torque. \n\nCrafted from high quality stainless steel, the Xforce Varex Cat Back Exhaust System features mandrel bent