J2 Engineering J2DP001 Stainless Steel Exhaust Downpipe for FRS/BRZ Made of High Quality T-304 Stainless Steel with Computerized Mandrel-Bends for Strength and Durability TIG Welded CNC Machine Flange for Strength and Durability Increase Engine Output and Efficiency; Gain 10 - 15 Horsepowers 2.75" Inlet / 2.75" Outlet / 2.75" Piping Diameter Fit 2013+ Scion FR-S & Subaru BRZ (Professional Installer is Highly Recommended, No Instruction Included)