These 3d printed ball bearing mazes were personally designed by me using CAD software. I have been drawing mazes since I was in elementary school in the 80s. So once I got a 3d printer I knew what I wanted to make and sell. This means you aren't getting some lame computer generated maze. These are the real deal. In fact, the big one is so hard that I have to look at the paper I used to designed the paths on, because I can't remember how to solve it.