Developed for truck applications and other applications that require a long body muffler. Previous part number was 19131347. This muffler is considered an "S-Type" muffler when compared to the 401158 and used on the same application. Notched necks for clamp in installation using 1" wide band style clamps 18327 (clamps not included). Reversible design for installation flexibility. High-quality T-304 austenitic stainless steel will never rust. 100% welded construction for strength. Free Flow design for improved performance. High-temperature continuous-filament fiber (CFF) acoustic material for sound control. Natural mill finish can be brushed or polished prior to installation. Best of all it's made in the USA and backed by Borla(r)'s Million-Mile warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand.