MACH Force-Xp Stainless Steel Cat-Back Exhaust System w/Polished Tips BMW 340i (F30) /440i (F32/33) 16-18 L6-3.0L (t) B58Aggressive Sound: A free-flowing, transverse muffler is used to absorb high pitch tones producing a powerful sound and unleashing all available horsepower and torque. The muffler is finished with a high-temp powder-coated black finish and a stamped aFe power logo. Exhaust Valve: This -catback exhaust system incorporates a factory style exhaust valve which uses the factory exhaust valve motor (not included). The valve helps regulate, direct and control the flow of exhaust gases by opening, closing, or partially obstructing passageways depending on throttle position for maximum performance. Simple Installation: This MACH Force-Xp cat-back exhaust system uses factory mounting locations providing stability and a hassle-free installation. Dual 4" Polished Tips: Finishing off this system are dual 4" diameter, polished, 304 stainless steel tips. The tips come with a laser-etched aFe power logo for an aggressive style. Leak-Free Seal: High quality band clamps are used for a complete 360 degree sealing surface. Brushed 304 SS Construction: The performance cat-back exhaust system is constructed of 3" to 2-1/2" mandrel-bent, brushed 304 stainless steel tubing for maximum performance, corrosion resistance and strength eliminating cracking.