To launch, simply place the HandCopter's plastic shaft between both hands and spin counterclockwise. These colorful copters can be used for dozens of scientific investigations. Why won't the HandCopter work if launched clockwise? How does this simple 'toy' illustrate the Bernoulli Principle? Students can test different variables to determine what will make the HandCopter stay aloft longer or fly straighter. Illustrate the principles of gravity, force, and motion as well as the principles of flight including camber, lift, center of gravity, and momentum. Each package contains five HandCopters. Colors may vary.