These pipes adapt a 3" header collector to a 2.75" mid-pipe. 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(r) stands behind every connection pipe with a Million-Mile Warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand.