Specification: PU / Polyurethane Filling Material: Sponge Diameter: 63mm Weight: Approx. 13g/pc Package: 9* Sponge Ball Solar System Ball: Planet Ball Toy Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Moon, Neptune in the universe. Sponge Ball: The planet ball is made of high quality material and filled with sponge. The planet ball is small and light, Suitable for children, it can improve children's color recognition ability and imagination. Solar System Stress Balls: 9 innovative planetary shapes that can be used as teaching aids for children. Let children understand astronomy, the ideal model of teaching aids. Educational Toys: Let your children understand the earth more vividly, and the beautiful colors attract children's attention. Environmentally friendly and non-toxic, will not harm your child. IDEAL GIFT: Stretchy, Stress Resistant Solar Planet Balls are so much fun to give to kids as birthday and Christmas gifts. I think the kids will love it.