With the Kosmos Bouncing Planets experiment kit, children make their own colorful bouncy balls. The set contains special granules in five different colors as well as matching molds and a measuring cup. By mixing the granules with water, the materials bond in the mold and harden into elastic bouncy balls in a short time. This creative set from the pocket experiment series offers a playful introduction to simple processes and leaves room for custom color mixtures with a planetary design.