This exhaust is including the muffler is made in house after hours and hours of R&D. Made entirely of 304 stainless steel. This system sounds great with our turbo kits. This product can only be purchased along with a turbo system, it is not available for sale as an outright purchase! If you are purchasing a stage 1 or stage 2 hayabusa turbo kit and would like to have this shorty pipe and muffler please purchase it here and your kit will arrive with a shorty pipe instead of the dump pipe.