Learn about Lever & Linkages. Build 16 working models to explaine how Levers are used to increase a force for lifting heavey objects and how they change direction of motion . 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 principles. 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.