SP Concepts Street Pro 4.5 Slip-On Mufflers For Harley Touring Give your Touring bike a performance edge with SP Concepts Street Pro 4.5 Slip-On Mufflers. Designed to pair with OEM headers, they produce a deep, resonant bark while the perforated baffle ensures smooth airflow. Ceramic coating adds protection and style, with zero tuning required for installation. Features: Deep-sounding slip-ons that give your Bagger a bold bark while retaining OEM headers 4.5 muffler with perforated core baffle Ceramic coated for durability and style No tuning required