Cobra 909 Twin Slip-On Mufflers440044080 Product Description The rear is finished with a rolled scalloped tip, not a simple slash cut 4" Muffler body 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 1 4" perforated core for its traditional and recognizable Harley sound No unsightly external screws holding in the tip or core