The Buren 1000A watch movement, produced exclusively for Mido from 1954 to 1960, features a base plate derived from the AS 1131/1132 movement. Some later samples of the movement include a larger date function. Optional black rhodium plating is available for this movement. The Buren 1000A can be equipped with the optional Fonto regulator, which has a mobile stud carrier and an adjustable regulator pin-width. Another optional regulator for this movement is the Incastar regulator, which is unique in its use of a free oscillating hairspring fixed between two rollers to adjust its length, ensuring no isochronism error caused by the gap between the regulator pins. The Buren 1000A offers automatic winding and sweep seconds, as well as a date function.