Modern functional stackable floor shelving for the contemporary home. Add extra storage to your Stack Floor Shelf System with this "add-on" shelf. Buy this "add-on" Stack Floor Shelf if you want to stack several units on top of each other. To do this you will first have to buy the starter unit named "Stack Floor Shelf - Single". To this single shelf you can then add several more shelves to your setup by choosing this add on unit. You place this add on unit below the single unit and connect them with the S-bracket that follows the product. The shelves are aligned and fastened and put together using small dowels that connects the walnut wood pieces on the sides of the floor shelf.