Of their use, there is no end.
For what its worth. We found the DIY Mason Jars book to be more useful. As to the book on the left, really? Coat hangers? I’m just not seeing it in this house. Rather, I DO see it! I see broken glass from too heavy backpacks being tossed carelessly on top of a “hook”. Maybe I’m wrong, but you’ll have a tough time convincing me of it.