This 3" diameter Borla(r) Cat-Back(tm) system is designed specifically for the 1.6L engine in the GR Corolla. The system contains Borla(r)'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 and the dual mufflers deliver the aggressive ATAK(r) sound with no drone. The system has an Exhaust Valve. It features 4 polished T-304 stainless steel tips 2) 3.5" round (center) tips and 2) 4.5" round (outer) tips. Systems with black coated T-304 stainless steel tips and carbon fiber tips are also available. Borla(r) Cat-Back(tm) & 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(r) Sound of Power respected by motoring enthusiasts everywhere. Each system is built from premium high-quality 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. Best of all Borla(r) 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. Give your GR Corolla the power and sound deserves bolt on a Borla(r).