The Cortebert 661 is a mechanical watch movement that was introduced in 1928. It is based on the Urofa 58 movement pattern, which prioritizes space efficiency. This movement features an indirect sub-second mechanism and incorporates shock protection through the use of elastic pivots. The design of the pivots ensures a steady transition from the pivot to the thinner end of the staff, reducing the risk of breakage. The Cortebert 661 movement is manually wound and includes a sub-second function. It has been utilized since its inception in 1928.