Rainbow Building Blocks can be used as tunnels, little houses, hills or rocking chairs and beds for tiny dolls its up to your imagination. Represents the element of Air. Made of rubber wood with non toxic wood. Beautiful and Colorful, Rainbow Building Blocks offer different possibilities than conventional building blocks or planks. Inspires creativity, looks great even displayed at home. Children (of all ages!) love to nest or stack the colorful, unique blocks, or use them as an open-ended toy in pretend play.