Difference Between Full-Power and Reduced-Power Versions of the 413x Series

The full-power 4130 and 4131 have a 70-hour power reserve with bidirectional automatic winding. Internally, Dandong Movement Factory designates these as model ST-4510. The reduced-power versions of 4130 and 4131 offer a 55-hour power reserve, with the automatic module changed to unidirectional winding. All other structural components remain identical. Dandong Movement Factory’s internal designation for these is ST-4801, with the skeletonized version labeled ST-4802. Shanghai-produced 4130 and 4131 movements are available only in the full-power version. Buyers can verify the type simply by opening the case back upon receipt.