3 years & up. Build key foundations for letter formation with these natural looking stones, each one with a different pattern. As kids trace over the patterns from left to right, learning how to make shapes, the stones provide the sensory feedback needed to take the first steps in writing. Develops fine motor skills and the language necessary to talk about shapes and patterns. Also use them to make impressions in clay or dough, or use with sand, rice, and paint as part of a sensory tray. The durable rocks are suitable for indoor or outdoor use and wash off easily.