The Ghost Cube Xtreme by Recent Toys from the Mefferts range is a challenging puzzle for one person. The 12-sided design features a striking black and white geometric pattern. Since this three-dimensional puzzle offers no color guidance for orientation, you must rely entirely on the different shapes of the individual pieces. Every twist changes the silhouette of the object and requires strategic thinking and concentration. This complex shape-shifting puzzle challenges experienced puzzle enthusiasts and is ideal as brain training.