Grimm's Assembly Set Musical Ball RunChildren love assembling this ball run by themselves, sorting and placing the colors at their discretion. Resulting in a double spiral run, one can also have marble races: for example, you let run a wooden bead against the included bell. Who will be the winner? Which ball is the most quit running down the path? Which one makes the most noise? After a while, the ball run can be dissembled and arranged in a different color set up, so the fun starts