HI,
this is the ultimate spinner cap . There are many, but IMHO all have some problem and i couldn't find one to like . So for 5 min i designed this one.

The details:

1. Its rounded so your finger sits there comfortably
2. Separation from bearing, so it clicks in place and is kept straight in its place
3. its diameter is designed so that you see a bit of the bearing for better aesthetics
4. STL is exported properly with high detail so it does not look edgy
5. All, even edge blends are made for beautifull print with standard nozzle