Pypes Exhaust Turbo Pro Mufflers feature flow control channels that eliminate drone, resonance, and flow turbulence while maintaining a steady flow of exhaust gases that result in a truly quiet performance exhaust note. The flow progression of this muffler mimics the CFM of a straight pipe without the annoying drone or resonance. Expect a quiet mellow tone with a true performance sound with the Turbo Pro Muffler. This 409 stainless steel welded case muffler is designed to withstand the output of today's big motors and comes with Pypes' famous lifetime warranty.