For use with Borla(r) Axle-Back systems 11889 and 11890 to connect to Resonator 60560. By using 11889, S-Type Axle-Back system with these pipes and muffler 60560 you will lower the sound level to "Touring". By using these pipes with 11890 ATAK(r) Axle-Back system and muffler 60560 you will lower the sound level to S-Type. Use ONLY with Borla(r) systems. It is NOT designed to work with competitor or Original Equipment systems. 2.25" diameter part. Built from premium T-304 stainless steel, superior to T-400 series (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 mid pipe with a Million-Mile Warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand.