The Howe Power X is made differently than most X-pipes with four separate pipes for the same type of smooth transition used in a merge collector. The Power X can be used with mufflers but works great without as well. The exhaust will emit a noticeably higher pitch with the X sounding like you picked up 500 rpm's.
Howe
Racing Enterprises
3195 Lyle Road
Beaverton, Michigan 48612