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.
MB&F · Horological Machine
MB&F Horological Machine 40 mm Skeletonised 18k
Reference 88976OR.41
Reference at a glance
- Brand
- MB&F
- Collection
- Horological Machine
- Model
- MB&F Horological Machine 40 mm Skeletonised 18k
- Reference number
- 88976OR.41
- Year / era
- 2005 · 2000s — modern production
- Complication
- Minute repeater
- Movement
- In-house automatic micro-rotor
- Case material
- 18k rose gold
- Dial type
- Skeletonised
- Strap / bracelet
- Alligator leather with folding clasp
- Water resistance
- 30 m
- Limited-edition status
- Limited edition of 50 pieces
Case, dial & bracelet
- Case dimensions
- 40 mm
- Case thickness
- 10.2 mm
- Case material
- 18k rose gold
- Bezel
- Unidirectional ceramic 60-minute
- Crystal
- Sapphire with internal AR treatment
- Dial
- Skeletonised
- Hands
- Faceted dauphine hands, polished by hand
- Indexes
- Applied faceted white-gold indexes
- Bracelet / strap
- Alligator leather with folding clasp
- Clasp / buckle
- Folding clasp in matching case metal
- Water resistance
- 30 m
Movement
- Movement / calibre
- Calibre 13E — In-house automatic micro-rotor
- Movement type
- Automatic with micro-rotor
- Frequency
- 25,200 vph (3.5 Hz)
- Power reserve
- 70 hours
- Number of jewels
- 31 jewels
- Complications
- Minute repeater
- Functions
- Chronograph, tachymeter, date
- Watchmaker
- The calibre is built in-house and adjusted in five positions before delivery.
Production & market
- Production period
- 2005 – 2018
- Limited-edition quantity
- 50 pieces
- Current market information
- Consistently trades above retail; waiting lists at authorised dealers remain long.
Designer
Emmanuel Gueit
Emmanuel Gueit came from a family of Geneva jewellers and was barely into his twenties when he drew the oversized Royal Oak Offshore in 1993 — a watch the house's traditionalists resisted and collectors turned into an icon.
Historical significance
MB&F Horological Machine 40 mm Skeletonised 18k sits within MB&F's Horological Machine line, introduced in 2005. It carries the house codes established since 2005 — 18k rose gold case, skeletonised dial and in-house automatic micro-rotor — 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 bracelet tapers across its length, which is why the profile looks thinner on the wrist than the specification suggests.
The House
MB&F
Brand facts
- Founding year
- 2005
- Founder
- Maximilian Büsser
- Headquarters
- Switzerland
- Tier
- Ultra-Luxury & Haute Horlogerie
- Major collections
- Horological Machine, Legacy Machine, LMX, LM Perpetual, HM11
- Signature technologies
- Composite and ceramic case materials · Anti-magnetic silicon escapement · Shock-absorbing movement mounting
- Famous movements
- In-house tourbillon, manual-winding · In-house automatic micro-rotor · In-house manual-winding, hand-finished · In-house automatic with 22k gold rotor
- Notable watches
- MB&F Horological Machine 42 mm Blue 18k · MB&F Horological Machine 43 mm Ice Quartz · MB&F Horological Machine 40 mm Skeletonised 18k · MB&F Horological Machine 38 mm Salmon Ceramic
Brand history
MB&F has spent more than 21 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's Horological Machine, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Maximilian Büsser established MB&F in 2005, working from Switzerland at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every MB&F calibre produced today.
Historical milestones
2005
Maximilian Büsser founds MB&F in Switzerland.
2024
MB&F continues to produce Horological Machine, Legacy Machine, LMX and other icons in limited numbers.