Very straightforward hooks that mount securely into standard US style pegboard (1/4in holes on a 1in grid). The part that locks into the lower hole is a little fat so that the hooks fit snug to the board and do not move when in use. These little guys are my favorite way to run out the last dregs of a spool of filament. Several variations have been attached but I am happy to upload more if anyone has specific needs.
The author marked this model as their own original creation.