This is a replacement driver for sealed bearing stock wheels that the came on Fit bikes for the past 5+ years.
The driver includes pre-pressed bearings, pawls and springs. This allows to a direct swap using only a wrench to remove the drive side collar.
*the tiny spacer that goes between this driver and the bearings for your wheel is NOT included. This tiny spacer is crucial to the function of this driver, be careful not to lose it while installing.
Fit calls this the King Kong Driver.