Khrome Werks 4-1/2" HP-Plus® Slip-On Mufflers With Race Tip - Chrome - Twin Cam804000358 Product Description 4 1 2" 16 gauge muffler body These mufflers have been dyno tested and show a 12% increase in torque and 7% increase in power Engineered for performance, style, and sound Absorptive baffle wrapped with stainless steel mat and high temp fiberglass Produce the Khrome Werks signature authoritative tone without annoying high frequency noises Improved torque and horsepower from the hit of the throttle Billet aluminum tips can