Front view
Dial, hands and bezel as delivered.
Case-back view
Case-back engraving and, where fitted, the sapphire display.
Movement
Calibre with its finishing and decoration.
On the wrist
Worn shot for proportion and strap drape.
Seiko · Astron
Seiko Astron 38 mm Mother-of-pearl Sapphire
Reference 91212OR.45
Reference at a glance
- Brand
- Seiko
- Collection
- Astron
- Model
- Seiko Astron 38 mm Mother-of-pearl Sapphire
- Reference number
- 91212OR.45
- Year / era
- 2009 · 2000s — modern production
- Complication
- Time only
- Movement
- High-accuracy quartz
- Case material
- Sapphire crystal case
- Dial type
- Mother-of-pearl
- Strap / bracelet
- White rubber velcro strap
- Water resistance
- 100 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 38 mm
- Case thickness
- 10.2 mm
- Case material
- Sapphire crystal case
- Bezel
- Fluted 18k gold
- Crystal
- Sapphire with internal AR treatment
- Dial
- Mother-of-pearl
- Hands
- Rhodium-plated baton hands with luminous fill
- Indexes
- Applied faceted white-gold indexes
- Bracelet / strap
- White rubber velcro strap
- Clasp / buckle
- Titanium deployant clasp
- Water resistance
- 100 m
Movement
- Movement / calibre
- Calibre 43E — High-accuracy quartz
- Movement type
- Manual-winding
- Frequency
- 21,600 vph (3 Hz)
- Power reserve
- 10 days
- Number of jewels
- 21 jewels
- Complications
- Time only
- Functions
- Annual calendar, moon phase
- Watchmaker
- Finishing, assembly and timing are carried out in the manufacture's own atelier.
Production & market
- Production period
- 2009 – 2024
- Limited-edition quantity
- Not applicable
- Current market information
- Trades close to retail on the secondary market, with steady demand for full-set examples.
Designer
Jörg Hysek
Jörg Hysek left Rolex and Seiko's European studios to build a design practice in Geneva, giving houses such as Vacheron Constantin, Breguet, Seiko and TAG Heuer their sculptural, architecture-led cases before founding his own brand, HD3.
Historical significance
Seiko Astron 38 mm Mother-of-pearl Sapphire sits within Seiko's Astron line, introduced in 2009. It carries the house codes established since 1881 — sapphire crystal case case, mother-of-pearl dial and high-accuracy quartz — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- The reference was originally planned as a one-year run and stayed in the catalogue for well over a decade.
- The movement's bridges are decorated even where they will never be seen once the watch is cased.
- The case is finished by hand, alternating polished and satin-brushed surfaces in a single pass so the edges stay razor sharp.
The House
Seiko
Brand facts
- Founding year
- 1881
- Founder
- Kintaro Hattori
- Headquarters
- Japan
- Tier
- Japanese
- Major collections
- Prospex, Presage, King Seiko, Astron, 5 Sports
- Signature technologies
- In-house hairspring production · Proprietary case-hardening and polishing · Hand-applied guilloché dials
- Famous movements
- Eco-Drive solar quartz · High-accuracy quartz · Spring Drive · Automatic, 24 jewels
- Notable watches
- Seiko Prospex 36 mm Green Stainless (1952) · Seiko Prospex 38 mm Black 18k (1977) · Seiko Prospex 38 mm Meteorite Platinum (1972) · Seiko Prospex 42 mm Green Sapphire (1997)
Brand history
Seiko has spent more than 145 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's Prospex, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Kintaro Hattori established Seiko in 1881, working from Japan at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Seiko calibre produced today.
Historical milestones
1881
Kintaro Hattori founds Seiko in Japan.
1899
Seiko earns its first international recognition for precision timekeeping.
1969
The quartz era forces Seiko to redefine mechanical watchmaking.
1990
Seiko enters the modern collector market with its signature lines.
2024
Seiko continues to produce Prospex, Presage, King Seiko and other icons in limited numbers.