The possibilities are endless with the Wonderworld Rainbow Sound Blocks. Babies will learn sorting, matching and association skills. Looking through the blocks, children will see the world in different colors. The Wonderworld Rainbow Sound Blocks are comprised of wood and transparent multi-colored plastic, and are filled with rattling beads that produce different tones when shaken. Wonderworld Rainbow Sound Blocks are the ideal toy for children who enjoy stacking and constructing objects. Your little one will love discovering the new and exciting sounds produced by this toy. Environmentally friendly rubberwood & strictly using non-toxic paints, dyes & lacquers & formaldehyde free glue. Blocks are hollow and filled with beads that produce different tones.