The Eterna 12825 watch movement, produced from 1964 to 1972, was specifically designed for the Ocean Star model and features a lever for releasing the stem from the dial side. The movement's finish, including that of the rotor, does not correlate with the production date. For a detailed description of the technical aspects, please refer to the Mido 1147OC. In terms of functionalities, this movement offers automatic winding, a sweep second hand, adjustable day display within a +/-24h range, quickset date adjustment via repeated crown pushing, Incabloc Shock Protection, and a day and date display.