I bought these for an awkward closet where there is only one shelf and then a lot of empty space above it. These make it like you have two shelves. You can stack items below and above. If you buy more than one you can even create another space between the two. I bought two and assembled and installed both within 5 minutes.

Pros: Super easy to assemble, no screws or tools needed
Cons: Only 2 color options