This system features the aggessive BORLA® ATAK® muffler and Polyphonic Harmonizer Technology which utilizes patented units that contain pipes of different diameters and lengths to create multiple exhaust notes that harmonize to deliver a clean, rich, full-bodied sound without any drone. It was designed specifically for the Silverado 1500 ZR2 and Sierra 1500 AT4X and features 2.75" turn down tail pipes. BORLA® Cat-Back™ & Axle-Back exhaust systems feature patented straight-through and multi-core technology to unleash hidden horsepower. Increased exhaust velocity adds power, driving excitement, fuel economy, and the distinctive BORLA® Sound of Power respected by motoring enthusiasts everywhere.
 
Each system is built from premium T-304 austenitic stainless steel, superior to T-400 series knockoffs (such as 409), to give you the absolute best in performance and durability. Ultra-smooth mandrel bends ensure maximum flow & power, and precision computer numerical control (CNC) manufacturing ensures an accurate fit.