This is spool for lose filament, for example, sample filament material.
It is adjustable to fit samples from 80mm to 150mm in diameter.
Fits perfectly on samples from ColorFabb.
There are 2 versions of arms, the difference is on the hole at the end for hoking filament when not needed, one for 1.75mm and the other is for 3mm filamet.

Parts needed:
3x M3x10mm screw
3x M3 nut
1x Z809 Ball-bearing