6+ months The center of each ring is the same size, allowing it to be stacked in any order for frustration-free play. Explore big & small, sorting, sequencing and building! The Stacks of Circles promotes early STEM learning by teaching a child about: - Sorting - Size - Sequencing - Building - Weights - Different / Same Inspire the Senses ™ Play at each stage! At 6+ months different sized rings are shaped to allow baby to easily grasp, bring to midline, chew and explore the textures with their mouth. At 9+ months baby may begin to place the rings onto the center post. The post is straight and all of the rings have the same size hole allowing baby to stack in any order desired! At 12+ months baby may begin to understand the concept of big and small. Adults can show baby how to stack the smallest rings first or the largest rings first to build a tapered stack! Additional Product Details Straight post accepts different sized rings, strengthening hand-eye coordination Chunky rings make it easy for baby to grasp, strengthening fine motor skills Teach color recognition by naming them as baby stacks each ring Count to 8! Each ring is numbered for counting Newsweek Best in STEM award winner 2021 #80758 5” L x 4.5” W x 9” H