XR-1(r) Multi-Core Racing Muffler. 3" Center Inlet/ 3" Center Outlet 4.25" x 7.88" Oval x 16" Long Body 21" Overall Length. Compact size is perfect for applications with limited space and can be used on a wide range of vehicles. It features BORLA(r)'S patented Multi-Core 4 tube design for maximum flow, horsepower, and torque. The Multi-Core portion of XR-1 mufflers flows better than straight tubing. Recommend for high horsepower applications. Reversible design for installation flexibility. T-304 Stainless steel for superior corrosion resistance. Natural mill finish can be brushed or polished prior to installation. 100% welded construction for strength. High-temperature continuous-filament fiber (CRF) acoustic material for sound control. There is no BORLA(r) logo embossment on this part. Best of all, it's made in the USA. Just what you’d expect from the world’s most experienced (and most winning) exhaust brand.