Fitment Information Honda Civic Coupe Si (2012, 2013, 2014, 2015) Coupe only Specs & Features 76mm/ 3 inch, Bolt-on system; no welding or fabrication necessary. May be compatible with other trim levels, however, will require basic welding and fabrication. 76mm Exhaust Product Description Skunk2 MegaPower exhausts are built for the performance enthusiast who wants a race exhaust system that features maximum exhaust flow and power production.  Skunk2 exhausts feature race sized exhaust piping that results in an exhaust system that is typically louder than most but has very little exhaust flow restriction.  Skunk2 MegaPower exhausts feature JDM spec N1 exhaust styling and a computer generated exhaust flow pattern that allows exhaust gas to flow at maximum capacity, producing big power gains. Skunk2 MegaPower Exhausts Feature: T304 Stainless Steel Construction Robotically TIG Welded for strength CNC Machined mandrel bends for smooth flow and a precise fit Skunk2 removeable silencer and all necessary hardware is included