Add sound to your Quadrilla tracks with xylophone tracks that play a scale as the marbles race over them. Playing Tips Build the layout shown on the box and connect it to an existing Quadrilla set. Listen to your marbles as they descend along the xylophone rails. Reverse the direction of the rails if you want to play a different melody. Features • Marble track construction toy made from sustainable wood and non-toxic water-based paint • Includes 2 distribution blocks, 2 stabilizing rings, 8 marbles and a xylophone track. • The xylophone track plays as the marbles roll down • German-manufactured design inspired by the Da Vinci Circle • Helps develop spatial thinking and understanding of scientific, technological, architectural, artistic and mathematical (WTBAW) principles • Recommended by The Wall Street Journal as the perfect toy for teaching kids to code • Compatible with all Hape Quadrilla sets • Suitable for ages 4 and up