Eisenhardt "Sous Marine Automatic" diver's watch, likely produced in the 1970s. This model and similar watches branded as Eisenhardt were actually produced by the French watch manufacturer Yema and retailed under the Eisenhardt name for the German-language market. Movement Specifications Manufacturer: France Ebauches S.A. Caliber Name: FE 4611 Movement Type: Automatic (self-winding) mechanical movement Jewels: 17 functional jewel bearings, Functions: Hours, minutes, sweep center seconds, and quick-set day and date displays. Frequency: It operates at 21,600 vibrations per hour (vph). Power Reserve: Approximately 44 hours.