BORLA system is a True Dual design. This system was designed specifically for the Lexus RCF ('15-'24) and IS 500 ('22-'24) and features the classic S-Type sound level and dual 4" black chrome on T-304 stainless steel tips on each muffler assembly. 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. A system with bright chrome on T-304 stainless steel tips is also available. Add optional mid section 60738 to this Axle-Back system to create a Cat-Back system. Part number 60738 is designed to work ONLY with BORLA Axle-Back systems 11981 & 11981BC. Installation of 60738 REQUIRES cutting the mid section of the stock exhaust and welding inlet pipes to rear of the catalytic converters. The BORLA mid section features a merge X-Pipe and will increase the overall sound volume while maintaining the tone of 11981 & 11981BC. Give your car the sound that it deserves, bolt on a BORLA. All 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 & 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. System Features: Axle-Back Exhaust System, BORLA system is a True Dual design, S-Type Sound Level, 4" Black Chrome On T-304 Stainless Steel Tips, T-304 Stainless Steel Construction, Million Mile Warranty.