The Jaeger Lecoultre 11LO watch movement belongs to a series of movements that includes the 4200-4202, 4205-4207 designs. These movements were produced in approximately 1960 and are characterized by manual winding functionality and a sub-second display. There are differences in the combined setting for the escapement wheel and/or mobile stud carrier in later samples, and designations for varying bridge shapes may exist. Further details regarding the specific differences between the mentioned designations are not available.