Ikoso Large Sphere illustrates principles of geodesic design. It can be used as a model or a two-frequency alternate geodesic dome. Also makes a great decorative mobile. Ages 10 and up. Contents: Approximately 400 pieces including 6″ wooden struts, plastic connectors, a punching awl, stretcher stick, and complete instructions for making a geodesic sphere approximately 30″ in diameter. No glue or special tools needed.