This is universal spool roller unit & stand.
It uses 608zz bearings, no bolts and nuts are required to assemble.
Roller parts is 12cm long which should be fit for most of filament bobbin, I hope.
If you want to use roller units different ways, you can design a stand of your own to meet your requirement.
Instead of using two,only one roller-unit can be mounted on frame of 'prusa i3' style printer centering a hole of bobbin, if you design stand properly.
Push pin through hole of bearing and snap-in to the roller holder. You might need little force to do it. (Do not try assemble pin to holder without bearing, it might not be pulled out.)
Make 3 more.
Screw each into roller.
- Insert roller units to stand.