Taking apart a Hanayama Cast Puzzle is only half the challenge. Putting it back together again is the rest. Hashtag is a puzzle that combines four plate-like pieces interfering with each other in exquisite balance. Its unexpected movement cannot be imagined from the linear movement when playing, but will be instantaneous. Hanayama cast metal brain teasers have 6 levels of difficulty, and each puzzle is Mensa-rated. Level 4 puzzles are considered challenging by most puzzlers. Design by Mr. Yoshiyuki Odani and Kirill Grebnev.Details: Includes 1 puzzle For 1 player Level 4 For ages 12 and up