6 months & up. This sorter is perfect for on-the-go play and learning! No more hunting for lost pieces, six shapes are tethered to the corners of the sturdy plastic cube. Each shape is symmetrical and slides into place for shape-matching play. Encourages shape recognition, fine motor skills, sensory learning, tactile exploration, and visual-spatial skills. Strings are short enough to be safe and long enough for little hands to grab and explore freely. Safe to use for teething. Made of BPA-free, 100% food-grade silicone. Built for lasting durability and safety.