XR-1® Multi-Core Bullet Racing Muffler. 2.5" Center Inlet/ 2.5" Center Outlet (no neck) 3.5" Round x 14" Long Body 16.75" Overall Length. Designed for use on compact applications where no tail pipe or turn down is needed, or weld on your own tail pipe or turn down. Can be used on vehicles with rotary engines. It features BORLA®'S patented Multi-Core 3 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. T-304 Stainless steel will never rust. 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.