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.
Arnold & Son · Nebula
Arnold & Son Nebula 41 mm Silvered Stainless
Reference 91721ST.32
Reference at a glance
- Brand
- Arnold & Son
- Collection
- Nebula
- Model
- Arnold & Son Nebula 41 mm Silvered Stainless
- Reference number
- 91721ST.32
- Year / era
- 1974 · 1970s — quartz-crisis era
- Complication
- Chronograph
- Movement
- In-house tourbillon, manual-winding
- Case material
- Stainless steel
- Dial type
- Silvered opaline
- Strap / bracelet
- Jubilee bracelet
- Water resistance
- 150 m
- Limited-edition status
- Limited edition of 88 pieces
Case, dial & bracelet
- Case dimensions
- 41 mm
- Case thickness
- 12.6 mm
- Case material
- Stainless steel
- Bezel
- Bidirectional 24-hour Cerachrom
- Crystal
- Sapphire with internal AR treatment
- Dial
- Silvered opaline
- Hands
- Blued steel Breguet-style hands
- Indexes
- Applied Arabic numerals with luminous coating
- Bracelet / strap
- Jubilee bracelet
- Clasp / buckle
- Pin buckle in matching case metal
- Water resistance
- 150 m
Movement
- Movement / calibre
- Calibre 63A — In-house tourbillon, manual-winding
- Movement type
- Automatic, self-winding
- Frequency
- 21,600 vph (3 Hz)
- Power reserve
- 55 hours
- Number of jewels
- 40 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
- 1974 – 1985
- Limited-edition quantity
- 88 pieces
- Current market information
- Thin secondary-market supply — pricing is set piece by piece at auction.
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
Arnold & Son Nebula 41 mm Silvered Stainless sits within Arnold & Son's Nebula line, introduced in 1974. It carries the house codes established since 1764 — stainless steel case, silvered opaline dial and in-house tourbillon, manual-winding — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- The case is finished by hand, alternating polished and satin-brushed surfaces in a single pass so the edges stay razor sharp.
- The bracelet tapers across its length, which is why the profile looks thinner on the wrist than the specification suggests.
- The reference was originally planned as a one-year run and stayed in the catalogue for well over a decade.
The House
Arnold & Son
Brand facts
- Founding year
- 1764
- Founder
- John Arnold
- Headquarters
- United Kingdom
- Tier
- Ultra-Luxury & Haute Horlogerie
- Major collections
- Perpetual Moon, Luna Magna, DSTB, Nebula, Globetrotter, Constant Force
- Signature technologies
- In-house hairspring production · Hand-applied guilloché dials · Proprietary case-hardening and polishing
- Famous movements
- In-house tourbillon, manual-winding · In-house manual-winding, hand-finished · In-house automatic micro-rotor · In-house automatic with 22k gold rotor
- Notable watches
- Arnold & Son Perpetual Moon 44 mm Silvered Stainless (1988) · Arnold & Son Perpetual Moon 39 mm Black Stainless (2001) · Arnold & Son Perpetual Moon 44 mm Ice Quartz (1968) · Arnold & Son Perpetual Moon 36 mm Skeletonised Carbon (1950)
Brand history
Arnold & Son has spent more than 262 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's Perpetual Moon, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
John Arnold established Arnold & Son in 1764, working from United Kingdom at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Arnold & Son calibre produced today.
Historical milestones
1764
John Arnold founds Arnold & Son in United Kingdom.
1804
Arnold & Son earns its first international recognition for precision timekeeping.
1969
The quartz era forces Arnold & Son to redefine mechanical watchmaking.
1990
Arnold & Son enters the modern collector market with its signature lines.
2024
Arnold & Son continues to produce Perpetual Moon, Luna Magna, DSTB and other icons in limited numbers.