A burr puzzle, also known as an interlocking puzzle, consists of notched pieces of wood, plastic or metal that when put together creates a three-dimensional shape. This version is pretty simple and therefore relatively easy to make. It consists of 12 pieces of which 11 of are identical. The 12th piece is the similar except that it has a notch cut into the top surface which is the key to the solution. Build Instructions: https://www.instructables.com/id/Burr-Puzzle/ Solution Video: https://youtu.be/ZFlJCB1kEYU Purchase from Amazon: http://amzn.to/2k99zjQ