Dual inlet and dual outlet. Internal X-Pipe for increased performance and improved sound. Notched necks for easy clamp-on installation using 1" wide band style clamps (clamps not included). Reversible design for installation flexibility. High-quality T-304 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.