The types of freehubs and endcaps available depend on the wheel model, the model year, and the hub.
A reference chart for Reynolds can be found on our Reynolds Docs page or at this link: Freehub and Endcap Compatibility Chart-Reynolds
A reference chart for SUNringle can be found on our SUNringle Docs page or at this link: Freehub and Endcap Compatibility Chart-SUNringle