The ultimate technology kit for all future mechanical engineers, technicians and engineers. How does a manual gearbox work? What is a planetary gear? How do you make a windscreen wiper work? How do you build a sturdy bridge? This kit with 20 different models answers these any many other elementary questions from the subject areas of mechanical and structural engineering. Kit contains mini motor, switch, battery holder for 9V block battery (not included), numerous gear wheels and other gearbox parts. With detailed assembly instructions