BUILD IT! LAUNCH IT!! Fun and easy to build! Learn about stored energy while building the catapult launcher. Release the lever arm to launch the foam balls and watch them fly! The enclosed learning card is full of scientific facts, key words and assorted information presented in a fun way! This set includes the plastic catapult parts, 2 foam balls, 1 rubber band, 1 sticker sheet, 1 easy to follow instruction card and 1 learning card.