B.F.G. 158-31BrandB.F.G.Caliber158-31SizeFunctionVersionHandsStem8303Stem (subs.)Stem (2 pce)Balance staff29813Balance staff (subs.)Mainspring (subs.)Mainspring (subs.)BatteryWatchpartsPart NocaliberdescriptionoriginalArtno.401Winding stem8028303723Balance staff ST -shock-absorber80229813