Auto exhaust pipes are available in different structures Material:sus304,201,321,316L Three different typical structures We make all kinds of auto exhaust ... pipes.The flexible tube are widely in exhaust system installed between engine and muffler to decrease engine noise and vibration,absorb muffler pipe ... 304,201 or 202Bellows:sus321, 304 or 316Lwire braids:sus304 Auto Exhaust pipe