Features tuned length headers without heat shields that step from 1-3/4 to 2-1/4 to optimize exhaust gas velocity and scavenging and to maintain the perfect balance of exhaust flow and back pressure to ensure crisp throttle response and maximum roll on power. Merge collector also features handcrafted internal knife edging to further improve scavenging efficiency through the collector. Following the collector, the megaphone immediately tapers out to a 3-1/2 muffler body that expands to 4-1/2 for increased baffle area. Exclusive Vance Hines baffle features reverse cone engineering that allows maximum power yet emits the perfect exhaust note rumble for any hi-output motor, keeping its focus on performance. Pro Pipe Hi-Output retains the signature cues of the Vance Hines Black Line with its high temperature ceramic coating and contrasted machined billet end cap.