For Honda Accord CM 4Cyl Stainless Steel 4" Muffler Tip Catback Exhaust System TIG Welded CNC Machine Flange for Resistance Against Pressure and Corrosion Aggressive Deep and Smooth Tone Sound while Ensures Smooth Exhaust Gas Flow Dyno Proven to Instantly Increase 15 to 25 Horsepower or Low End Torque 4"(OD) Muffler Tip / 2.25"(ID) Inlet Application: 03-06 Honda Accord 2-Door 4-Cylinder (Instruction NOT Included, Professional Installer is Highly Recommended)