BORLA Axle-Back exhaust system 11984BC is designed to fit the 5.0L Mustang GT that is NOT equipped with Active Valve Performance Exhaust. Muffler contains 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. It features 4" black chrome on T-304 stainless steel tips and the aggressive ATAK sound level. Using BORLA Stainless Steel Polish p# 21461 is NOT recommended with these black chrome tips. We suggest cleaning the tips with hot water and a microfiber cloth. Systems with bright chrome on T-304 stainless steel tips, and carbon fiber tips are also avaiable. It fits both the coupe and convertible models. The straight-through and patented multi-core technology is 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.