Gibson CFT Superflow Dual/Dual Oval Muffler - 4x9x18in/3in Inlet/3in Outlet - StainlessGibson CFT Muffler actually tunes your exhaust by using resonance chambers, directional louvered tuning ports and angular induction to draw exhaust gases into the muffler and expel it at a higher velocity. They feature a Chambered and louvered core, Non packed muffler to ensures no sound degradation overtime and fully welded solid internal construction, This result delivers more power with a deep tone. Reversible.