This is a mount for holding KitchenAid mixer attachments that snaps onto the front bars of standard pantry shelves. I made them out of clear PETG. I printed it with the knob facing up, I had supports for the rod that the attachments mate with, and my infill was at 25% (gyroid). Here's the link to the Onshape cad file if you would like to make any edits.
The author hasn't provided the model origin yet.