A few millimeters of colored water sprite beads, soaked in water, can quickly become big beads with a diameter of more than 1 cm, and even give birth to small "beads". Such "magic" things naturally attract many children.

　　This kind of transparent beads, the size of rubber balls, are mainly red, yellow, blue, green, purple, orange, black, colorless and cyan, which are very eye-catching. They are packed in small plastic bags or small glass bottles. There are about 15~30 balls in each bottle, and the price is 0.5~1.0 yuan. Because they will change "magically" when put into water, they also have one. In some areas, it is also called Spongebob, Aquatic Life, Crystal Baby, etc.