Khrome Werks 4-1/2" HP-Plus® Slip-On Mufflers - Black With Turbine Tip831428340 Product Description 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 4. 5" 16 gauge muffler body Improved torque and horsepower from the hit of the throttle Produce the Khrome Werks signature authoritative tone without annoying high frequency noises Billet aluminum tips can be