Watery habitats filled with swirling waves, beautiful shells, and fascinating corals will immerse children into imaginary underwater worlds that will inspire play, promote creativity, and enhance language development. Each sensory stone is engraved on one side and smooth on the other to encourage open-ended small world play.Easy to set up and easy to pack away. Set contains 18 stones – 6 each of 3 designs. Size approximately (1-3/4" x 2").