Discover the forces that defy gravity with this fun and fascinating kit. The contents of this kit include items that demonstrate lift, drag, and thrust. The easy to understand instructions clearly explain the principles at work. Contents: Instruction sheet Helicopter balloon set Half bouncy ball Bouncy ball Discovery Tubes are compact science kits, designed to provide easy experiments and entertaining lessons using the items in the tube and common household goods. They're fantastic for school projects, day care providers and summer camps.