WatchesAtlas / Watch knowledgeThe Watch EncyclopediaUnderstand the details that make a watch.Explore watches ↗Find a term or abbreviationCategoryAll categoriesMovements & mechanismsComplications & displaysCases, dials & braceletsFinishing & craftsmanshipPerformance & measurementModern watch technologyCollecting, condition & careSearchAllABCDEFGHIJKLMNOPQRSTUVWXYZ1 termsClear filtersMovements & mechanismsUnidirectional windingAn automatic winding system that uses one direction of rotor rotation to wind the mainspring.↗