Discovering Stem Mechanics Pulley Drives. New in Factory Sealed Box. 10 pages of theory and amazing facts, 3 pages of experimental activities, 2 pages of revision quiz, and 15 pages of step by step instructions, also 3D interactive instructions. 8 models to build. Stationary Bike, Crane Bridge, Blender, Construction Crane, etc.. Learn how Pulley drives can be used to transfer force with reduced friction and how they increase force or speed at amazing levels. Pulleys have been used for thousands of years and are essential parts of complex machines in modern times solving many technological problems. For ages 8-16 and up.