Manually operated 4-speed gearbox with reverse and an integrated transfer case, providing a hands-on demonstration of power transmission and gear reduction systems. Equipped with dual levers for speed selection and gear reduction, the model includes constant mesh gear pairs that engage alternately for precise torque control. The cutaway design exposes key components, such as the clutch, main and transmission shafts, gear reducers, and control forks, offering a comprehensive understanding of the gearbox’s internal mechanics and its application in heavy-duty and off-road vehicles.