HATTORY-SEIKO 2101ABrandHATTORY-SEIKOCaliber2101ASizeFunctionVersionHandsStemStem (subs.)Stem (2 pce)Balance staffBalance staff (subs.)Mainspring (subs.)Mainspring (subs.)BatteryWatchpartsPart NocaliberdescriptionoriginalArtno.721Balance cplt. -regulated310-2109840310210