Amazing Science Surprises: Colorful Spheres Balls in Test Tube-Zanny Marbles Science Principles explored in this kit: chemistry, applied science Zanny Marbles (Multi Color/5g about 300 balls) in Test tube Kit included: a clear plastic test tube with twist-on plastic cap. and the amazing colorful Spheres" that absorb up to 400 times their weight in water to become slimy jelly balls that BOUNCE. You won't believe this incredible stuff! Learning Science gone fun. Kid can study this process in a test tube environment. This keeps kids fascinated for hours. Multipurpose: Have Fun Learn Science, Toys-Games, Gifts. Eco-Friendly Non Toxic. Reusable up to 2 years.