Add sound to your Quadrilla tracks with xylophone tracks that play a musical scale as the marbles race across them. Playing Tips Build the layout shown on the box and connect to an existing Quadrilla set. Listen to your marbles as they travel down the xylophone tracks. Reverse the direction of the tracks to play a different melody. Features • Marble run construction toy made with sustainable wood and non-toxic water-based paints • Includes 2 distribution blocks, 2 stabilizer rings, 8 marbles and a xylophone track. • Xylophone track plays as the marbles travel down the track • German-made design inspired by the Da Vinci Circle • Helps develop spatial thinking and an understanding of science, technology, engineering, art and mathematics (WTBAW) principles • Touted by The Wall Street Journal as the perfect toy to teach kids to code • Combines with all Hape Quadrilla sets • Suitable for ages 4 and up