The Nine Glow in the Dark 3-D Planets by University Games are an educational collection of our solar system and a fun addition to any room. The nine spheres range in size to represent each or our planets. Twenty-five feet os string and adhesive putty is included to suspend the planets from your ceiling. They range in size from about 1 inches downward. A fine science project! Not appropriate for under the age of three as there are small parts. Ages 5 and up.