Transverse Flow design. Transverse flow mufflers were originally designed for GM F-Body Camaros and Firebirds. On these vehicles they were mounted behind the rear axle and were parallel to the axle. This muffler can also be used to create custom systems on other vehicles. Single 2.5" Offset Inlet/ Dual 2.5" Offset Outlets. The inlet and one outlet are on one end of the muffler, and the second outlet is on the opposite end. 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.