Based in the fantastic work of @11b30b4 for this prop: https://www.thingiverse.com/thing:2765967 I decided to customize a little my kit of electro-binoculars with a different top knob. But I ended doing three of them, so you can choose the one you like more.

I tried to design it as if it were part of an old camera or equipment.

Knob is directly based in @11b30b4 design so it will fit the overall aesthetics
Knob2 is simpler and looks sturdier. As the previous one, the center hole will accept a screw (about M3). So it's possible to make it movable.
Knob3 is designed having in mind a thumb-screw (like those in some PCs) for the center hole.

BQ Prusa i3 Hephestos

Doesn't Matter

No

0.06

20

I used Fusion 360 for this design.