These specially designed Tactile Shells are an innovative sensory play resource as they're made from 100% eco-friendly materials and consciously manufactured with reduced energy and water usage. They are made of natural Fiber Particulate Composite (FPC). Each shell has its own natural grain as a result! Children will love to touch and feel these shells, make imprints into sand and dough or use them in role play. They can be used to teach early math concepts such as sorting, matching, comparing, sequencing, patterning and counting. The set includes 36 tactile shells, 2 of each in 6 different tactile finishes and 3 sizes. For ages 18M+. Sizes: 1.6"W, 1.9"W and 2.1"W.