Add sounds to your Quadrilla tracks with xylophone tracks that play a musical scale as marbles race across them. Playing Tips Build the layout shown on the box and connect it to an existing Quadrilla set. Listen to your marbles as they travel down the xylophone tracks. Reverse the track direction to play a different melody. Features • Marble track building 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 marbles roll down • German-made design inspired by the Da Vinci Circle • Helps develop spatial thinking and an understanding of scientific, technological, engineering, artistic, and mathematical (WTBAW) principles • Touted by The Wall Street Journal as the perfect toy to teach kids to code • Compatible with all Hape Quadrilla sets • Suitable for ages 4 and up