Pack of 3 steel marbles for use with Cuboro mysterycube.

Cuboro is a unique, Swiss-made wooden marble run that is the best-in-class for marble runs.  High quality, and endless in its combinations, inventor Matthias Etter's Cuboro and Cugolino marble runs truly are "marble runs for a lifetime."What it does: An ingenious building block and marble run toy from Switzerland, Cuboro allows endless combinations and designs.