Big Boulder is bought as a set of five models.-2x Parts 1-2 of 5 (2x THIS)-2x Parts 3-4 of 5 -1x Part 5 of 5 Big Boulder is a blatant case of twisty puzzle extremism. 1 core, 60 centers, 140 corners and a whopping 150 edges. That is a lot of pieces. And to make it more complex, this puzzle jumbles too, which means that some moves may be blocked by other pieces. This puzzle is based on the geometry of a Pentagonal hexecontahedron. You may want to look that up on Wikipedia. The object of the puzzle is to scramble it and then solve it to a state where each color only touches itself or black.Watch the YouTube video Read at the Shapeways Forum Read more at the Twisty Puzzles Forum Please contact Oskar directly if you are interested in obtaining a fully colored and assembled sample of this puzzle.