This muffler is directional. The outlet can be identified by the mounting bracket welded to the endcap. The world's first mufflers purpose-built to optimize the sound & power of crate and custom-built motors. 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. 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.