The kit replaces the stock head pipe and mufflers with large-diameter, free-flowing head pipes and matching Street Cannon mufflers. The muffler inlet diameter is increased to 2.25 inches to enhance exhaust gas scavenging and the catalysts are relocated to the mufflers to enhance flow. The 4-inch-diameter Street Cannon mufflers are tuned to provide a deep bass exhaust note and a healthy rumble at idle, and that famous Harley sound throughout the RPM range. The mufflers are EPA stamped and the system is 50-state legal and CARB approved. This High Flow Exhaust System fits 2010-later Harley-Davidson Touring models but does not fit Trike models. Separate purchase of Screamin’ Eagle 4-inch muffler end caps and ECM recalibration (priced separately) is required.