Pencil holder for metal shelving

I needed a solution to clear my surfaces in my workroom so I designed this little holder for pencils and small tools, etc. This works with shelving that has rods spaced about 19 to 20mm apart. The rod at the edge of the shelving that it slips over is about 7mm diameter.

This works really well so I may add more items later on.

For light items, an infill of 20 is fine. In Cura, I chose 'nowhere' for 'fill gaps between walls' to reduce print time so the thinner walls in my print have no infi