The Maker Studio Propellers Set by ThinkFun Game is designed by Engineers for Budding Engineers. The Maker Studio Propellers Set inspires imagination and a love for engineering for your child. In this set featuring propellers, your child will be able to build a chopper, a biplane, a windmill and a plane. For each build you are given Engineering Challenges – experiment with friction, torque and propulsion as you engineer your solutions. Once your child has mastered all four builds, they can get creative and design something that’s all their own while learning engineering principles! Features: 1 X-Linkage1 Spool2 Extra Long Connectors, 3 Long Connectors, 4 Short Connectors2 Small WheelsOne 5.5" Rod, Three 4.25" Rods, Five 1.5" Rods24 Hub Caps1 Hole Punch3 Rubber Bands10 Engineering Challenges Awards: Creative Child Magazine Preferred Choice Award, Educational Builder Construction Toys PAL ( Play Advances Language) Award Suitable from 7 Years +