These three wooden shakers make a very soft, comforting sound, and have shapes that are more interesting for infants to grasp than a simple rattle. The set features three endangered animals: the amur leopard, the long-eared owl, and the leatherback turtle, while the package insert provides information about them and related conservation efforts. Each shaker measures between 8 cm and 10 cm (about 3" and 4") long. Musical instruments are excellent for the development of physical coordination, motor skills, sensory processing and a sense of rhythm.