The Fatboy is at home in the worlds most prestigious concert halls, famous jazz clubs, and everywhere in between. Its our best-selling barrel, and for good reason. Artists who are called upon to interpret a wide variety of music appreciate the Fatboy Barrel’s unique flexibility and versatility. Note: In Japan, this model is known as the Backun Barrel. Standard Fit Backun, Buffet, LeBlanc, Selmer (USA, Centered Tone, 10G, Series 9), Yamaha, and most other model brands. Most clarinet brands will be Standard fit, but please note that handmade instruments or very old instruments may have sizing differences that cant be foreseen. Selmer Paris instruments not listed above (for the most part) have a slightly different socket depth, and you must be sure to order the Selmer fit. Generally, Selmer fit uses increments that end in 0.5mm increments (Ex. 65.5mm). If youre not sure, please contact us before ordering. Standard Plus Special Order Same as above with larger bore for more free blowing feel Selmer Paris Fit Special Order Selmer Paris Fit (Not including Selmer USA, Centered Tone, 10G, Series 9)