Set of 20 pieces includes 3-piece pendulum, 6 cones, 2 launch balls, 1 windmill, 2 goal cups, set of decorative stickers, and set of challenge cards. Kid-powered pendulum launcher: no batteries, springs, or rubber bands. You control the force. Encourages trial and error approach to problem solving through game-like challenges. Early introduction to concepts such as force and momentum. Pendulum stands approximately 7¾" tall.