I bought these in the lighter color....my first reaction when I opened the box was, "wow, these are a little smaller than I thought!" But, I never bothered to really check the sizes.  
These are definitely not crates for any kind of storage,(unless it is decorative) thankfully I intended to use them as shelves.  They have small silver plates over the corners of each one, which look great once they are on the wall.
Although they were different then I thought they would be, I LOVE them and think they are the PERFECT pieces for what I needed them for!  We just hung picture hangers on the back and hung them like that.

The picture shows the large one and smallest one on the left wall and the medium one on the wall to the right of the picture!