Khrome Werks 4.5" HP Plus Slip-On for M8 TouringThese mufflers have been dyno tested and show a 12% increase in torque and 7% increase in power 4 1 2" 16 gauge muffler body Absorptive baffle wrapped with stainless steel mat and high temp fiberglass Engineered for performance, style, and sound Produce the Khrome Werks signature authoritative tone without annoying high frequency noises Improved torque and horsepower from the hit of the throttle Optional performance inserts boost low end performance