smallest knob - OpenSCAD

I wanted to hang my new broom on the wall. Actually, a simple screw would have been enough, but that was too ugly for me. That's why I developed this little button. The requirement for this button was to be as small as possible, to make the screw look nicer and also to have a ring so that the broom would not slip off easily.
The button can be easily adapted to other requirements using OpenSCAD.