Simple lace locks or anchors. You can purchase them off Amazon, but it was quicker to model and print them for a fraction of the cost. The circle is meant for round/athletic shoelaces and the other is for flat shoelaces. I printed both and they worked just fine on my flat shoelaces.
Don't be fooled by the small size. They worked perfectly for my adult size shoelaces on my slip-on Converse.
The author marked this model as their own original creation.