Three identical parts create a perfect, heavy, and pleasant-to-the-touch ball made of metal –
When each part constitutes a third of the ball and the total weight is over 1 kg

It's easy to take it apart, but it's surprising how difficult it is to put it back together.
Even the planning of the project for production took about two years until the finished product, which was crowdfunded on Kickstarter and raised over $150,000 to start the first production series.

Its parts move in perfect coordination, similar to the aperture of a camera.
And to assemble it, you have to precisely align six different points at the same time – but not all six points can be seen at once.
And even after you crack the solution, you'll find yourself coming back to it again and again – because it's so fun, enjoyable, and satisfying.

For the solution, click here.