IWC 41 Brand IWC Caliber 41 Size Function Version Hands Stem 5441 Stem (subs.) Stem (2 pce) Balance staff 28120 Balance staff (subs.) Mainspring (subs.) Mainspring (subs.) Battery WatchpartsPart NocaliberdescriptionoriginalArtno.401Winding stem8025441445= C412Setting lever spring94200445C412721BBalnace cplt. -for shock-absorber9420072141723Balance staff ST -shock-absorber