Having installed hundreds of exhausts on the S550 Ecoboost Mustangs over the past few years, we can say with a great deal of certainty that the MBRP Race exhaust system is one of the most popular systems on the market - and for good reason! The exhaust system consists of a factory connection style y-pipe, that quickly jumps up to a full 3" T409 tubing into a dual split rear section with the MBRP Race mufflers and out to the dual 4.5" tips. We do not recommend the aluminized tubing for our customers, only the T409, as it's less likely to cause any problems with rusting. This exhaust fits all 2015+ Ecoboost Mustangs, and any 2018+ Ecoboost Mustang without active exhaust. MBRP claims that this will not fit convertibles, due to the under-chassis bracing.