Big sporty sound! Larger diameter of pipes improves exhaust gas flow to muffler. Engine performance will be improved. Durable and good looking with SUS304.   STAINLESS STEEL HIGH PERFORMANCE FRONT PIPE. Front Pipe decreases secondary exhaust gas back pressure of turbine to improve response. Stainless steel is durable and good looking. Flanges are also made of stainless steel and tig welded that reduces exhaust gas friction.