This is a ball bearing spool holder that mounts on two pegboard hooks to hold the spool above your printer.
To assemble it, you'll need two 608 bearings, a length of 5/16" threaded rod and two nuts. Make sure the washers are mounted with their shoulders facing inward, toward the bearings, to make sure the bearings can spin freely.
You will need to print two hanger blocks, two outside spacers, two washers and one spacer to make a spool holder wide enough for a (MakerFarm) 1Kg filament spool.
The holder mounts on two long pegboard hooks, 4" apart.