This 2.25" diameter Cat-Backâ„¢ system features a Merge X-Pipe for increased performance and improved sound. The exhaust exits thru single 4.5" round polished T-304 stainless steel tips on each side for a sharp appearance. The system contains BORLA'S 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 to the BORLA®, mufflers. The mufflers then enhance this sound to the character and volume appropriate for our aggressive ATAK sound. This system comes with our no drone guarantee. BORLA Cat-Backâ„¢ and Axle-Back exhaust systems feature patented straight-through and multi-core technology designed 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 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. Best of all BORLA stands behind every system with a Million-Mile Warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand.