Manufacturer Seiko Caliber Number 6R54, 6R54A Movement Type Automatic, self-winding mechanical Diameter 27.4mm Casing Diameter 27mm Height 5.3mm Jewels 24...
NH34
Manufacturer Seiko Instruments (SII), Time Module Caliber Number NH34, NH34A Movement Type Automatic Lignes 12”’ Diameter 27.4mm (29.36mm w/ spacer)...