Josef Prusa is a knob... selector dial for the Prusa i3 (MK2/MK3).

Nothing but love for Josef, thanks for everything you have done for the 3d printing community!

Also, check out my collection of Prusa i3 Selector Dials:
https://www.thingiverse.com/lylesvendsen/collections/prusa-i3-selector-dials

Print instructions

Most printing materials should work, but I printed this one in PETG with a 0.1 layer height