XR-1® 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®'S patented Multi-Core 2 tube design for maximum flow, horsepower, and torque. The Multi-Core portion of XR-1® mufflers flows better than straight tubing. Reversible design for installation flexibility. T-304 stainless steel will never rust. 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® 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.