The spiral flow louver muffler is a six-inch round by thirty-inch long stainless steel case, containing an inner packing material made of stainless steel wool, with a ceramic blanket outer packing material. The interior of the muffler is a one piece four-inch stainless steel tube that dampens the resonance of diesel exhaust and still keeps the interior noise level of the cab within comfortable levels of the original factory sound level.

The MBRP muffler design uses a spiral flow louver that is specifically designed for diesel exhaust performance. The spiral pattern of the louvers promotes the same twist the turbocharger introduced to the exhaust gasses as they left the turbocharger housing. The spiral flow of the louvers helps speed the exhaust gasses out of the exhaust system to lower the exhaust gas temperatures as quickly as possible.