The Hubsmith rear hub can come with a number of freehub bodies. The standard 2 speed is the default freehub equipped on most Hubsmith rear hubs. For the last several years, the so-called standard 3 speed freehub has made into the market in significant quantities. The standard 3 speed freehub can comfortably accommodate 3 cogs (but not 4 cogs safely), and is compatible with 11T or 12T cogs, but not our proprietary 10T cogs. The latest version is the one on the left in the picture, which has full length splines. It can accommodate 3 or 4 cogs safely, when using 11T or 12T as the smallest cog. It is also 10T cog compatible through an adapter, and can accommodate upto 5 cogs when using the 10T cog.