The Cortebert 529 watch movement is an open face calibre movement that features a Breguet hairspring. It is optionally equipped with Reed's regulator. The differences between the Cortebert 529, 162, and 165 are not known. The movement registers list only the open-face variant of the Felsa 161, while Ronda additionally includes the Cortebert 529, 162, and 165. The Cortebert 529 movement includes functions such as stem wind and set, sub second, and was commonly used around the year 1932.