This is a smaller width filament spool, and with selectable diameter depending on where the brackets fit.

I created it to store filaments I make from PET bottles, and I wanted a smaller spool with a larger inside diameter.

It was designed to require a very small amount of filament.

Bracket housing holes can be used to clamp the filament.

I have included the source in FreeCAD in case you want to make your own version.