These 2.75" diameter Over Axle Mid-Pipes are recommended to be used with the Borla(r) Axle-Back system and X-Pipe to complete a Cat-Back(tm) system. 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 over axle pipe with a Million-Mile Warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand.