hks exhausts systems are designed for direct bolt on fitment to the stock flanges and come with all the necessary gaskets and hardware to provide simple installation and long term durability. all hks exhaust systems utilize a micro-fiber mesh sheet wrapping around the internals of the muffler tube to prevent muffler packing from escaping over time, thus increasing the durability of the system. hks full stainless steel exhausts system applications also now come with an extended 4-year warranty