Learn about Pulley Drives. Build 8 working models to explain how to transfer force with reduced friction and increase speed. . Create a material lift or a windmill. Building instructions supplied with further builds available online. Booklet provides experiments, detailed explanation and learning quizzes. Stem instructions and workbooks included. Multiple builds possible. Online model plans. Fully compatable across all engino systems. Develops stem priciples. Size H27, W37, D5.5cm. For ages 3 years and over. Manufacturers 3 year guarantee. WARNING(S): Not suitable for children under 3 years old. Only for domestic use. This product contains abs, tpe and nylon. To prevent possible injury by entanglement remove this toy when the child starts trying to get up on its hands and knees into a crawling position.