The Factory Fatty is reminiscent of the "works" or cone pipe once used by Factory Teams. It shares many of the same characteristics with its&&';; craftsmanship and material quality. The Factory Fatty broadens and smoothes out the power curve while boosting gains throughout the entire power band, more low-end, more mid, and increased over-rev. No matter what type of riding you do, the Fatty has the benefits you&&';;re looking for. -Lighter 20 gauge steel used for the body of the pipe. -19 Gauge steel used for the header portion. -Includes O-rings on most models -Hand pounded seams for smooth flow transitions. -O-Rings Included