The repackaging muffler is a 6-inch x14-inch round carbon fiber repackaging muffler with a 2.25-inch, 2.50-inch or 3-inch free-flowing spiral straight-through core wrapped in a stainless steel mesh. T304 stainless steel end plates and hardware. Automatic carbon fiber. 4-inch DX3 "L diagonal line prompt. If there is no muffler, the noise can reach more than 100 decibels at a certain speed. Secondly, engine noise and tire noise. When the automobile is running normally, the engine noise can reach more than 90 decibels, and when the tire noise speed exceeds 90 km/h, it can reach about 95 decibels. Therefore, adding a muffler to the exhaust system can reduce the exhaust noise of automobiles by 20-30 decibels. On the engine side, replacing diesel engine with gasoline engine can reduce engine noise by 6-8 decibels.