This versatile block set is a delight for your child's eyes, ears, and building hands. Each of the wooden blocks has 2 transparent panels in different colors and is filled with rattling beads that produce different tones when shaken. Children can look through the panels to see the world in a new hue, shake the blocks to create original musical compositions, and build an endless variety of structures before returning all the blocks to their wooden storage case. Wonderworld toys are made in Thailand from environmentally friendly rubber wood. They strictly use non-toxic paints, dyes, and lacquers with formaldehyde-free glue. Their packaging is made from at least 70% recycled paper.