I'm honestly not really sure. I think my mom has a magazine somewhere that has a name of it. I was perusing her stash of magazines and saw this rail type block.. It's just a 2.5" colored strip inside and 1.5" strip of WoW on each side and it's trimmed down to a square, so I think they are finished 4" blocks.. it took me awhile to figure out a good layout, so the layout itself is my "design" so to speak.