Plan toys are committed to protecting the environment, as well as keeping your child safe and entertained. All their toys are made from non-toxic materials, like the Baby's First Block sets, wooden blocks with different forms of sensory stimulation like touch, sight and sound. The Balancing Monkeys is a toy cleverly disguised as a math game, requiring your child to calculate the number of monkeys needed on each side of the tree to balance it. The set includes six monkeys with interlinking arms made of sturdy wooden material.