This is my improved chainlink hook, tested by teenagers learning to weld. They hang their helmets on these. A few were broken--they now have 60% infill and a fuzzy skin surface treatment, as well as having had fillets added around the projecting hook for strength. They are holding up pretty well.
To install, place the top hook, then pop the bottom one on using a screwdriver or similar tool. I used PETG for its strength and the degree of flexibility that allows for installation without breaking the hook. They are meant to be tight. If your fencing is a little different in size, just 2 or 3 percent in change, up or down, can be applied in the slicer (yes, we ran into this).
The author marked this model as their own original creation.