You manufacturers have to divulge these things!!! I have been looking everywhere for a Fox40 190mm air shaft assembly. Totally out of stock!!!! Then I happened upon a suspension rebuilder web site and they mentioned that the Fox 40 internals were the same units as the Marzocchi!! BINGO!! I order one up. Fits great, easy to install. Best of all I actually found it in stock. Others are buying the 203mm version, cutting it down and charging a small fortune for it. Thanks so much for having this assembly in stock. Happy birthday to me!!