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.
Sinn · 903
Sinn 903 41 mm Skeletonised Ceramic
Reference 28208OR.68
Reference at a glance
- Brand
- Sinn
- Collection
- 903
- Model
- Sinn 903 41 mm Skeletonised Ceramic
- Reference number
- 28208OR.68
- Year / era
- 1981 · 1980s — quartz-crisis era
- Complication
- Annual calendar
- Movement
- Quartz
- Case material
- Ceramic
- Dial type
- Skeletonised
- Strap / bracelet
- NATO textile strap
- Water resistance
- 200 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 41 mm
- Case thickness
- 12.6 mm
- Case material
- Ceramic
- Bezel
- Bidirectional 24-hour Cerachrom
- Crystal
- Sapphire with internal AR treatment
- Dial
- Skeletonised
- Hands
- Skeletonised sword hands, white luminescent
- Indexes
- Applied Roman numerals
- Bracelet / strap
- NATO textile strap
- Clasp / buckle
- Folding clasp in matching case metal
- Water resistance
- 200 m
Movement
- Movement / calibre
- Calibre 20E — Quartz
- Movement type
- Automatic with micro-rotor
- Frequency
- 25,200 vph (3.5 Hz)
- Power reserve
- 38 hours
- Number of jewels
- 31 jewels
- Complications
- Annual calendar
- Functions
- Annual calendar, moon phase
- Watchmaker
- Assembled and regulated by a single watchmaker, who signs off the piece before casing.
Production & market
- Production period
- 1981 – 1996
- Limited-edition quantity
- Not applicable
- Current market information
- Consistently trades above retail; waiting lists at authorised dealers remain long.
Designer
In-house design studio
The reference was drawn by the manufacture's internal design office, where case, dial and movement architects work alongside the watchmakers rather than as an outside commission.
Historical significance
Sinn 903 41 mm Skeletonised Ceramic sits within Sinn's 903 line, introduced in 1981. It carries the house codes established since 1961 — ceramic case, skeletonised dial and quartz — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- Early production dials show a slightly different minute track, and collectors pay a premium for them.
- The bracelet tapers across its length, which is why the profile looks thinner on the wrist than the specification suggests.
- The movement's bridges are decorated even where they will never be seen once the watch is cased.
The House
Sinn
Brand facts
- Founding year
- 1961
- Founder
- Helmut Sinn
- Headquarters
- Germany
- Tier
- Affordable & Tool Watches
- Major collections
- 556, 104, EZM, U1, 903, Hydro
- Signature technologies
- Anti-magnetic silicon escapement · Shock-absorbing movement mounting
- Famous movements
- Automatic, 38-hour reserve · Automatic Powermatic 80 · Automatic COSC chronometer · Quartz
- Notable watches
- Sinn 556 42 mm Silvered 18k (1975) · Sinn 556 43 mm Slate Sapphire (1961) · Sinn 556 36 mm Mother-of-pearl 18k (1976) · Sinn 556 43 mm Ice 18k (1965)
Brand history
Sinn has spent more than 65 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's 556, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Helmut Sinn established Sinn in 1961, working from Germany at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Sinn calibre produced today.
Historical milestones
1961
Helmut Sinn founds Sinn in Germany.
1969
The quartz era forces Sinn to redefine mechanical watchmaking.
1990
Sinn enters the modern collector market with its signature lines.
2024
Sinn continues to produce 556, 104, EZM and other icons in limited numbers.