With well over 35 years of racing experience behind it, the Fatty Gold Series pipe delivers race proven performance. The 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. More tractable power, improved throttle control Provides power gains throughout entire power band Carbon steel with a nickel plated finish for maximum durability FMF Racings Tru-Flo stamping process ensures a perfect fit and optimum performance. Can be used with FMF or stock silencer (unless noted) Our most popular 2-stroke pipe O-Rings Included 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 Fits: Honda CR125R 2005-2007