XR-1(r) Multi-Core Slim Line Racing Muffler. The Center Inlet / Center Outlet necks are 3.5" tubing formed into a 4.13" x 2.61" Oval. The body is a 3" High x 7.88" Wide Oval, 12" Long with a 17" Overall Length. Designed for high horsepower applications in low profile vehicles with limited space including vehicles with rotary engines. It features BORLA(r)'S patented Multi-Core 2 tube design for maximum flow, horsepower, and torque. The Multi-Core portion of XR-1(r) mufflers flows better than straight tubing. 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 T-304 stainless steel wool 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.