HATTORY-SEIKO 8121 Brand HATTORY-SEIKO Caliber 8121 Size Function Version Hands Stem Stem (subs.) Stem (2 pce) Balance staff Balance staff (subs.) Mainspring (subs.) Mainspring (subs.) Battery Watchparts Part NocaliberdescriptionoriginalArtno.4018121Winding stem03547659840354765.8121MAIN PLATE(PLASTIC)01017749840101774.8121TRAIN WHEEL BRIDGE01257759840125775.8121CENTER WHEEL AND PINION02217769840221776.8121FOURTH WHEEL AND PINION02417769840241776.8121Hour wheel02717769840271776.8121Setting lever03837559840383755