Installation REQUIRES cutting the O.E. system. BORLA system eliminates the O.E. resonators. This Cat-Back system fits both the 2016-2017 IS200T and the 2018-2024 IS300. System features 4.25" x 3.5" oval polished T-304 stainless steel tips and the classic S-Type sound level. BORLA Cat-Back 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 and power, and precision computer numerical control (CNC) manufacturing ensures an accurate fit.