I wanted to have a safe hook for keys and towels in a campervan. They should stay on the hook even if the campervan made brutal movements at road holes or similar. I used a carabiner before but that was not what I wanted.
The form should allow relatively easy handling and no accidental loss. The upper part allows to hang something quickly if no movement is expected tor the near future.
The second (07) thing is an earlier design which will work but which I didn't develop further.