Three Cubes by Cubic Dissection

"Three Cubes by Kohno Ichiro is an award-winning design placed in the top 10 2018 IPP Design Competition results. This pocket-sized puzzle is a ton of fun and remains a favorite. With only three identical pieces, this seemingly simple assembly puzzle may keep you busy for longer than you expect. The goal is to combine the pieces to create a stable assembly forming three distinct, equal-sized cubes. Complicating this task is the polarity of the powerful magnets embedded into pieces.

Once solved, the puzzle snaps into shape, resulting in a beautiful and entertaining fidget toy. Three cubes were only the beginning; Mr. Ichiro subsequently designed the Four Cubes and Five Cubes to create a set, with each puzzle escalating in difficulty.

Mr. Puzzle posted a great video review of Three Cubes.

This batch of Three Cubes was constructed from striking planks of Canxan. Approximately 65 copies are available. Three Cubes ships in an unsolved configuration."