I use these for square pieces of stained glass for classes I take. There’s enough room in each slot to hold several pieces of glass making it very easy to find the color I looking for.
I was tired of folders getting lost under something else and the flat stacks that I had (2 ea 4 high) took up a quarter of my usable desk area. I replaced both of them with this one unit. It’s easier to see my folders & it takes up less than 1/2 of the bin areas.