This has become one of our most sold pieces! The Sheepey Built B Series hood exit header is made of 18 gauge 304 stainless stainless steel. It's runner size of 1 7/8" steps to a 2inch tube size. These runners merge into a 4 to 1 collector then exit to a megaphone with reverse cone. This is the same header that is used on the world famous “M80” all motor car making over 300 WHP all-motor and running a best of 10.2 in a 92 civic hatch.