CHRONOSWISS C121BrandCHRONOSWISSCaliberC121SizeFunctionVersionHandsStemStem (subs.)Stem (2 pce)Balance staffBalance staff (subs.)Mainspring (subs.)1.35x10.0x0.11Mainspring (subs.)Ersatz: 820 3315 0BatteryWatchpartsPart NocaliberdescriptionoriginalArtno.771Mainspring AUT sliding attachemnet99900771C121