The Einstein Collection Six Square Challenges - Tricky Puzzle Set - 3D Brain Teaser Puzzles By Professor Puzzle.Calling all puzzle enthusiasts & Albert Einstein fanatics. Contains an outer placeholder, 16 wooden cubes and 6 brain teasing challenges. Develop your problem solving skills Work your way through the six different challenges by correctly arranging the set of wooden cubes. As part of the official Albert Einstein Collection, a set of puzzles and brain teasers.