3 yrs. & up. A flexible resource with great child appeal, Sorting Stones offers the opportunity to explore color, shape and pattern in a wide variety of contexts including sand, water and small world play both indoors and outdoors. Cast from a unique mix including real stone, each durable stone measures 40-45mm and has a colorful bug character engraved on one side. Each set includes 20 stones, with five bug body shapes - circle, square, rectangle, triangle and hexagon, in four colors - red, blue, yellow, and green.