At first, I couldn't figure out how to put them together. The instructions are horrible, and I couldn't get the pieces to stay connected. (If you're struggling, too, just bend the tabs so they're straight across the opening. Then the pieces will snap together easily.) Once I figured it out, they were simple to put together.They're probably not the sturdiest boxes in the world. They're fine to stack on top of each other, but I wouldn't stack anything heavy on top of them.They were just what I needed though so I didn't have to play shoebox tetris anymore. It's so convenient to just be able to open the door and grab the shoes I want, even if they're at the bottom of the stack. I wound up buying these in several sizes. The only additional comment I have on the boot sized boxes, is that I wish the door had been placed on the long side of the box, instead of the front. This size will not fit on the width of a standard closet shelf with the door facing front/out like the others will. It has to be longways across the shelf, so you need to leave extra space for the doors to open.