ProXS Muffler 3" Center Inlet/ 2.5" Dual Outlet, 4" x 9.5" Oval, 19" Long Body, 24" Overall Length. Notched necks for easy clamp-on installation using 1" wide band style clamps using 1) 18330 and 2) 18325 (clamps not included). Reversible design for installation flexibility. This muffler is generally used in a system that has a single inlet and dual outlets, but it can also be installed in a system with dual inlets and a single outlet. High quality T-304 austenitic stainless steel for superior corrosion resistance. 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. Alternate muffler with Un-Notched necks is 40349. If clamping, use band clamps 18004 & 18006.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.