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.
A. Lange & Söhne · Zeitwerk
A. Lange & Söhne Zeitwerk 40 mm Slate Grade
Reference 27753OR.84
Reference at a glance
- Brand
- A. Lange & Söhne
- Collection
- Zeitwerk
- Model
- A. Lange & Söhne Zeitwerk 40 mm Slate Grade
- Reference number
- 27753OR.84
- Year / era
- 2008 · 2000s — modern production
- Complication
- Chronograph
- Movement
- In-house automatic micro-rotor
- Case material
- Grade 5 titanium
- Dial type
- Slate grey
- Strap / bracelet
- Jubilee bracelet
- Water resistance
- 50 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 40 mm
- Case thickness
- 8.1 mm
- Case material
- Grade 5 titanium
- Bezel
- Octagonal with 8 hexagonal screws
- Crystal
- Anti-reflective sapphire, double-domed
- Dial
- Slate grey
- Hands
- Rhodium-plated baton hands with luminous fill
- Indexes
- Applied faceted white-gold indexes
- Bracelet / strap
- Jubilee bracelet
- Clasp / buckle
- Pin buckle in matching case metal
- Water resistance
- 50 m
Movement
- Movement / calibre
- Calibre 78B — In-house automatic micro-rotor
- Movement type
- Automatic with micro-rotor
- Frequency
- 28,800 vph (4 Hz)
- Power reserve
- 55 hours
- Number of jewels
- 21 jewels
- Complications
- Chronograph
- Functions
- Perpetual calendar, leap year
- Watchmaker
- Assembled and regulated by a single watchmaker, who signs off the piece before casing.
Production & market
- Production period
- 2008 – 2016
- Limited-edition quantity
- Not applicable
- Current market information
- Trades close to retail on the secondary market, with steady demand for full-set examples.
Designer
Gérald Genta
Gérald Genta (1931–2011) trained as a goldsmith in Geneva and became the most influential watch designer of the 20th century. Working freelance, he sketched the Audemars Piguet Royal Oak overnight in 1970, followed by the Patek Philippe Nautilus, the IWC Ingenieur SL and the Bulgari Bulgari — defining the integrated-bracelet luxury sports watch as a category.
Historical significance
A. Lange & Söhne Zeitwerk 40 mm Slate Grade sits within A. Lange & Söhne's Zeitwerk line, introduced in 2008. It carries the house codes established since 1845 — grade 5 titanium case, slate grey dial and in-house automatic micro-rotor — 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 movement's bridges are decorated even where they will never be seen once the watch is cased.
- The bracelet tapers across its length, which is why the profile looks thinner on the wrist than the specification suggests.
The House
A. Lange & Söhne
Brand facts
- Founding year
- 1845
- Founder
- Ferdinand Adolph Lange
- Headquarters
- Germany
- Tier
- Ultra-Luxury & Haute Horlogerie
- Major collections
- Lange 1, Saxonia, Odysseus, Datograph, Zeitwerk, 1815, Richard Lange
- Signature technologies
- Composite and ceramic case materials · In-house hairspring production
- Famous movements
- In-house tourbillon, manual-winding · In-house manual-winding, hand-finished · In-house automatic with 22k gold rotor · In-house automatic micro-rotor
- Notable watches
- A. Lange & Söhne Lange 1 40 mm Slate Platinum (1978) · A. Lange & Söhne Lange 1 39 mm Green Stainless (1969) · A. Lange & Söhne Lange 1 44 mm Blue Quartz (1954) · A. Lange & Söhne Lange 1 41 mm Silvered Quartz (1973)
Brand history
A. Lange & Söhne has spent more than 181 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's Lange 1, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Ferdinand Adolph Lange established A. Lange & Söhne in 1845, working from Germany at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every A. Lange & Söhne calibre produced today.
Historical milestones
1845
Ferdinand Adolph Lange founds A. Lange & Söhne in Germany.
1885
A. Lange & Söhne earns its first international recognition for precision timekeeping.
1969
The quartz era forces A. Lange & Söhne to redefine mechanical watchmaking.
1990
A. Lange & Söhne enters the modern collector market with its signature lines.
2024
A. Lange & Söhne continues to produce Lange 1, Saxonia, Odysseus and other icons in limited numbers.
More Zeitwerk
A. Lange & Söhne Zeitwerk 40 mm Meteorite Quartz
Ref. 65470OR.56
A. Lange & Söhne Zeitwerk 42 mm Blue Carbon
Ref. 30433OR.72
A. Lange & Söhne Zeitwerk 43 mm Black Ceramic
Ref. 99059OR.86
A. Lange & Söhne Zeitwerk 37 mm Mother-of-pearl Stainless
Ref. 50369ST.58
A. Lange & Söhne Zeitwerk 39 mm Blue Sapphire
Ref. 26587OR.11