All parts from the engine to the last piece. Install, enjoy, and be thrilled when you turn it off. The muffler is silent and well-known. 🔸/ Fox Skyline electronic muffler, 2.5 inch size with a final connector, 2.5 inch. 🔸/ Headers, 2.5 inch. 🔸/ Downpipe. 🔸/ The muffler is compatible with computer and cutters.