PLM Private Label Mfg. Power Driven 3" Non-Resonated Midpipe Kit for Subaru WRX STI 3" 2015-2021 was made for maximizing HP gains, more flow, more power, more torque & more sound!Precision CNC mandrel bend tubing allows for a constant tubing diameter throughout the bend, which results in precise fitment as well as improved exhaust gas flow.  Each system is fitted with a straight pipe to eliminate the resonator, includes stainless steel flanges, and area direct fit to our muffler deletes / axle-backs (sold separately) to be finished off with a straight-through, low-restriction racing muffler for uninterrupted flow.Applications: Subaru WRX & STi 2015 - 2021 This product does not work with SPT axle back exhaust systems. Key Features: Made of Stainless steel One year limited warranty Replacement grade 8 bolts & nuts CNC machined flanges Stainless steel casting on the Y-collector. Precision CNC Mandrel Bent 3" split to 2.5" Gaskets and bolts included Non-resonated piping - amazing sports car sound! Professionally TIG welded and assembled Direct bolt-on easy installation to PLM axle-back Note : This product may not fit other axle back systems