HATTORY-SEIKO 1520A Exploded diagram Brand HATTORY-SEIKO Caliber 1520A Size Function Version Hands Stem 351-152 Stem (subs.) Stem (2 pce) Balance staff 315-120 Balance staff (subs.) Mainspring (subs.) Mainspring (subs.) Battery WatchpartsPart NocaliberdescriptionoriginalArtno.401BWinding stem9840351152