The Buser 105 is an open face calibre mechanical watch movement with a Breguet hairspring. It shares similarities with the Cortebert 616 and 618 movements, although the exact differences between these models are not known. It is speculated that the Cortebert 618 may have been specifically made as a variant for Rolex and Panerai. The Buser 105 movement features stem winding and setting, as well as a sub second function. It was commonly used around the year 1945.