I have only put one of the two of these that I purchased together so far, but that one is perfect. They hold a ton of books…which is great, since we have more than a ton. I would recommend using book ends if possible though. The opening between the leg and the wall is just large enough that normal size hardcover books will just pop out of the side and end up on the floor. We put larger books on each end to hold them in place until I can find some book ends I like.