The Shake, Rattle & Chew box is a sensory rattle & teethable set to encourage baby’s developing auditory, fine motor, and communication skills. At about 4+ months, baby is learning to explore different textures, materials, and learning to grasp, shake, reach, and bat with their hands. They touch & put everything in their mouths, but it is their way of discovering the world around them. They start experimenting with sound, by cooing & gurgling, and shaking things to hear what they do.