The BORLA? Axle-Back system for the fifth generation Forester is tailored specifically for the 2.5L Boxer engine. It provides a more aggressive sound over the stock system without adding any drone. The 11966 weighs less than the factory system, and features a 3.5? black coated T-304 stainless steel tip. Ultra-smooth mandrel bends ensure maximum flow & power, and precision computer numerical control (CNC) manufacturing ensures an accurate fit. System bolts directly to the OE mounting points for ease of installation. A polished tip is also available on system 11966.