Offers the best power delivery yet! Designed to come off the throttle super clean, for excellent low-end throttle response and power. It delivers power smoothly in the mid-range with an increase in power on the top and more over-rev than stock. Hard-anodized aluminum muffler shell with stainless steel tubing. Features cone-style outlet cap and inlet cone to keep the muffler as forward as possible for centralized mass. Meets new 2007 AMA® 99 dBA sound requirement. Head pipe has special patent-pending resonant chamber design. Completely rebuildable.