These large stones are designed to offer children exciting tactile learning experiences. The intriguing designs are ideal for exploring, matching and understanding symmetry. Made from a durable mix, they may be used both indoors and outdoors. The set includes four pairs of stones, with each pair interlocking in a different number of ways-from concentric circles that can be continually twisted to shapes that can be joined in two, three or four positions. Contains 8 - 3" stones.