US Patent 8684131 Dual muffler

A dual muffler is provided which includes an inlet pipe, an end of which an exhaust gas is introduced from an engine. Additionally, an outlet pipe, an end of which is connected to an opposite end of the inlet pipe, branched at the opposite end of the inlet pipe running toward a side and the opposite side such that the exhaust gas from the inlet pipe is discharged through an opposite end is also provided. A housing covers the inlet pipe and the outlet pipe to expose the end of the inlet pipe and the opposite end of the outlet pipe to an outside environment; and a sound-absorbing material fills the interior space of the housing except for the remaining space where the inlet pipe and the outlet pipe.