Three pieces each have two protrusions in the body of the screw. You need to take off in the United States are flattened together has been a complex intertwined to solve this in three dimensions. Design of molding House Akio Yamamoto of Japan.　 "The cause" and is? "Has caused" and the adult inspiration and logic to solve the puzzle. The Mission's "off." And "back to you". Simple, but profound. And take full advantage of the head and hands, I try to challenge you. Product specifications: ages: 6-year-old-difficulty: 6 (out of 6) size: 75 × 119 × 45 (mm) weight: 140 g