Reliability Backed for a lifetime- Armor Plus Series exhaust systems are crafted from corrosion-resistant T409 Stainless Steel - a value-oriented material designed to protect from penetrating rust and will stand up to almost anything you can throw at it. T409 Stainless Steel tubing is easy to clean. If you're looking for a performance exhaust system with a Lifetime Warranty, this is probably the one for you. If you don't find yourself faced with lots of precipitation and salt, this is all you're ever going to need. All of the tubing is mandrel bent for maximum exhaust flow. Mandrel bending ensures no rippling in the bends. The end result is that it gives you more fresh air inside your engine's cylinders, allowing it to produce more power and improve vehicle performance and longevity. It's important to note that T409 Stainless Steel is resistant to penetrating rust but winter conditions, heavy salt air, and road treatments might accelerate the corrosion process, these conditions are not covered by MBRP's manufacturer warranty unless the part or system fails completely. When it comes to a performance exhaust system, choose the MBRP ARMOR PLUS Series for a reliable option backed for a lifetime. MBRP, Stand out from the crowd with a perfromance exhaust system that sounds great. 2016-2018 Ford Focus RS, T409 Stainless Steel 3 Inch Cat Back Dual Outlet 3 Inch Cat Back, Dual Outlet 2016-2018 Ford-Focus RS 3 Inch Cat Back, Dual Outlet, T409 Rugged T409 Stainless Steel Construction Smoother Exhaust Flow Enhanced Exhaust Tone Smooth Mandrel Bent Tubing 4.5 inch OD Tips Included Gains Of Up To 7HP Increase Up To 8ft.lbs Torque Gains Up To 10 Percent Flow Increase MBRP's Armor Plus Series is the performance exhaust of choice for the enthusiast who needs a system that can take anything that the road throws at it.