Watch and listen - this marble run is a true sound experience! Once the glass marble is inserted into the red wooden ball, it starts making its way from higher tones to lower tones of the lower section. Plus: the fresh, complementary rainbow colours make this acoustic marble run a decorative eye-catcher in the nursery! Children love to experiment! By using all sorts of different marbles, you can perform exciting noise experiments with this elegant sound marble run: for example, what will it sound like with a bunch of marbles at once? How does the space between the marbles change the sound effect? There's plenty of long-lasting entertainment guaranteed here!