909-Twins 4-Inch Muffler Dresser 17-24909 Twins Slip On MufflersThe rear is finished with a rolled scalloped tip, not a simple slash cut The rolled tip is matched with an inner core finished with the same scalloped cut Inner tip is actually part of the constant velocity, tuned core that gives the muffler its great sound and performance Uses a 2. 25" perforated core for its traditional and recognizable Harley sound No unsightly external screws holding in the tip or core giving the muffler