The Henzi Pfaff 420 is a mechanical watch movement that was used between the years 1972 and 1979. It features optional plastic bushings instead of dial screws for enhanced functionality. The movement is equipped with an automatic winding system, allowing for continuous operation without manual winding. It also has a sweep seconds function, providing a smooth and fluid motion of the seconds hand. The day display can be set by adjusting the crown within a range of +/- 24 hours, while the date feature can be quickly adjusted by repeatedly pushing the crown. Additionally, the movement incorporates Incabloc Shock Protection, ensuring reliable performance under various conditions.