The Super CUBI Box is without a doubt one of the most challenging Karakuri boxes that you might ever encounter. Seriously! The solution requires a whopping 324 steps to open, using a simultaneous sliding sequence that must be maneuvered on 3 sides of the cube, back and forth, by sliding the wooden panels. When the panels move in the correct order, the lid will slide open on the 324th step to reveal the chamber of secrets inside. Like all puzzles from this family, the Super CUBI is impeccably designed and the quality is incredibly sturdy and long-lasting. The fun of this box in particular comes from a mathematically based solution, perfect for engineers (or aspiring engineers)!