Stack, nest, or snap together and roll. The center of each ring is the same size, allowing rings stack in any order! While stacking the rings from the biggest to the smallest, babies are understanding the concept of relative size. The Roly-Poly can swing in different directions which can train the baby's tracking ability and improve hand-eye coordination. High quality material, smooth surface, no sharp point or sharp edges to ensure infants safety playing. Coluorful rings can introduce your baby to different colors. Jingle-sounds on each ring. Helps foster fine motor skills. Introduces colours, pattern and relative size & shape. Encourages thinking & problem-solving skills. These Stack & Roll help strengthen thinking & problem solving skills by introducing baby to size, shape, how things fit together, and the concept of cause & effect that rewards babys actions with fun jingle sounds! Stacking and nesting together all help exercise babys fine motor skills and eye-hand coordination. Store in a cool and dry place China