FIND THE GAP

Children's shelf for storage.

I see the following gaps:

1. Shaky
2. Non transportable (too heavy to move and has no wheels)
3. Storage basins stand on two narrow rails (so all things can be stored only in basin)
4. Basins sometimes slip off the rails (content falls out)
5. Basin cannot be taken by one hand
6. Some basins are too large and heavy for child (especially when it is filled)
7. Basins do not occupy all available space between shelves
8. No lids for basins
9. Mostly impossible to store books
10. It has only one function - storage (*)

I decided to use as My Gap  - item with (*) in the list - extending functions of the shelf.