Parts & Accessories Spare parts Shake it for installation *Advantages of the dual muffler system: When the muffler is closed, it significantly muffles the car's sound. Accessories: BHP electronic dual muffler, 3 inches, with electronic dual valves Sport muffler, 2.5 inches Muffler device + 2 remotes + hose I installed it for 4 months and then removed it. It is clean and in good condition.