With Haba’s Melodious Building Blocks For Ball Track Construction Set, you can order and design the sound path that your marbles will take! If the blocks are ordered correctly, they form a pentatonic scale. The set contains: 1 track (32 x 4cm) 9 building blocks 6 melodious blocks 6 marbles. The melodious building blocks set is made in Germany. Safety information: Not for children under 3 years old. Danger of choking – small spheres Age: 3-10 years