Specifications: PU / Polyurethane Filling material: Sponge Diameter: 63 mm Weight: Approx. 13 g / pc Package: 9 * sponge ball Solar system ball: Planetary ball toys in the universe, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Moon, Neptune. Sponge ball: The planetary ball is made of high quality materials and is filled with a sponge. The planet ball is small and light, suitable for children, and can improve children's color recognition ability and imagination. Solar system stress ball: 9 innovative planet shapes that can be used as teaching aids for children. Make children understand astronomy, the ideal model for teaching aids. Educational toys: make your children understand the planet more vividly, beautiful colors that attract children's attention. Environmental protection and non-toxic, no harm to your children. Ideal gift: anti-stress solar planet balls with elasticity, very interesting, can be given to children as birthday and Christmas gifts. I think kids will like it.