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Jaeger-LeCoultre Master Control Calendar 40mm Stainless Steel
Ref. Q4148420
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Stepping up in Jaeger-LeCoultre's range
The Master Control Calendar sits at the centre of what Jaeger-LeCoultre does best: complications that are genuinely useful rather than merely demonstrative. The calibre 866AA carries a particular solution to a problem that defeats most calendar watches — the date hand jumps 90 degrees instantaneously from the 15th to the 16th, which means it never drifts across the moonphase and small seconds subdial at six o'clock. Both remain readable at all times, which sounds obvious until you see how many triple-complication dials sacrifice legibility to symmetry. At 10.95mm thick with a 47.2mm lug-to-lug span, this is a dress watch that wears honestly at 40mm — enough presence on the wrist without bulk beneath a cuff. The silver dial is light without being stark, and the dauphine hands carry luminous inserts that read without drawing attention to themselves in normal light. The movement behind it has completed JLC's 1,000-hour in-house protocol, tested cased up across six positions over more than 40 days — a discipline that goes well beyond standard certification and matters to anyone keeping this watch for the long run. The Novonappa calfskin strap changes without tools, which makes rotating straps practical rather than theoretical.
- Reference
- Q4148420
- Brand
- Jaeger-LeCoultre
- Collection
- Master Control
- Case size
- 40mm
- Case thickness
- 10.95mm
- Lug width
- 20mm
- Case material
- Stainless steel
- Case shape
- Round
- Dial
- Silver
- Crystal
- Sapphire
- Movement
- Automatic
- Calibre
- 866AA
- Functions
- Day-date, Small seconds, Moonphase
- Water resistance
- 50m
- Bracelet / strap
- Leather strap
- Strap colour
- Brown
- Clasp
- Folding clasp
- Lume
- Luminous
- Condition
- Pre-owned
- Retailer
- Mappin & Webb
Additional specifications
- Lug-to-lug
- 47.2mm
- Power reserve
- 70 hours
Learn more about Jaeger-LeCoultre
Antoine LeCoultre opened a workshop in Le Sentier in 1833 and set about solving a problem nobody else had: precise measurement. His Millionomètre of 1844 was the first instrument capable of measuring to a micron, and it let the Vallée de Joux move from skilled approximation to genuine precision.
The house became the movement supplier to the industry. Patek Philippe, Vacheron Constantin, Cartier, and Audemars Piguet all built watches on LeCoultre ébauches, and the manufacture has produced well over a thousand distinct calibres — an output no other house approaches. The partnership with the Parisian retailer Edmond Jaeger, formalised in the company name in 1937, gave it the Jaeger-LeCoultre it still carries.
Two products define it in the public mind. The Reverso of 1931 was designed so British Army officers in India could flip the case and protect the crystal during polo; the reversible case became one of the few genuinely original watch designs of the century. The Atmos clock, developed from 1928, runs on atmospheric temperature variation and needs no winding at all.
The Duoplan and the calibre 101 — still the smallest mechanical movement in series production, introduced in 1929 — sit alongside the gyrotourbillons and minute repeaters that keep the manufacture at the technical front.
Richemont has owned the house since 2000.
- 1833
- Antoine LeCoultre founds his workshop in Le Sentier.
- 1844
- The Millionomètre measures to the micron for the first time.
- 1929
- Calibre 101, the smallest mechanical movement, is introduced.
- 1931
- The Reverso launches with its flip case.
- 1937
- The Jaeger-LeCoultre name is formalised.
Also in 6 collections
This watch appears in Back in Stock (5,241), Stainless Steel Watches (3,391), Automatic Watches (1,792), Leather Strap Watches (1,111), Silver Dial Watches (757) and Dress Watches (569).
What the specifications mean
A slim watch on leather, made for wearing with a shirt.
Strengths
- 40mm suits most wrists
- Sapphire crystal, which resists scratching
- 70-hour reserve survives a weekend off the wrist
- Luminous hands and markers for low light
Worth knowing
- 50m suits rain and handwashing, not swimming
Jaeger-LeCoultre Master Control Calendar alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification | Q4148420 | 103368 | 224270 |
|---|---|---|---|
| Price | £9,850 | £9,995 | £9,450 |
| Case size | 40mm | 40mm | 40mm |
| Water resistance | 50m | 30m | 100m |
| Movement | Automatic | Automatic | Automatic |
| Strap | Leather strap | Ceramic bracelet | Stainless steel bracelet |
| Power reserve | 70 hours | 60 hours | 70 hours |
| This watch |
|
|
Your new watch
Frequently asked questions, and things you should know about this watch
Can I swim with it?
Showering yes, swimming no. 50m covers splashes and brief immersion, but a swimming stroke generates well above the pressure that figure describes.
Water resistance explainedWill the glass scratch?
Unlikely. Sapphire is second only to diamond in hardness and shrugs off everyday marking.
Sapphire, mineral and acrylic comparedDoes it need a battery?
No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.
Quartz, automatic and solar comparedHow long does it run for when it's not worn?
About 70 hours fully wound — enough to sit off the wrist over a weekend and still be running.
What size strap does it take?
20mm. Any strap of that width will fit, and on most modern watches quick-release bars make the swap a two-minute job with no tools.
Will it fit my wrist?
Lug-to-lug is 47.2mm, which suits wrists from roughly 16.5cm (6½ inches) upward.
Lug-to-lug decides fit more than case diameter does.
How to size a watch to your wristIs it a men's or women's watch?
Listed as men's, though at 40mm it sits in the range that suits anyone.
Cheapest place to buy
Mappin & Webb is the only UK retailer we track stocking this reference, so there is nothing to compare it against today.
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