Jaeger-Lecoultre Master Ultra Thin 1907 & Master Ultra Thin Grand Feu


The immaculate purity of time

To mark its 180th anniversary in 2011, the Manufacture Jaeger-LeCoultre honoured its founder Antoine LeCoultre by dedicating an exceptional thin watch to his memory: the Master Ultra Thin Jubilee watch. This creation with its case measuring a mere 4.05 mm thin represents an extraordinary technical feat that makes it one of the slimmest watches in its category. In 2014, the Master Ultra Thin line welcomes two new models featuring a blend of mechanical perfection, elegance and the ultimate expression of horological minimalism: the Master Ultra Thin 1907 and the Master Ultra Thin Grand Feu.

An encounter between two visionary minds
At the start of the 19th century, Antoine LeCoultre played a pioneering role by becoming the first to unite the entire range of watchmaking skills under one roof – as well as to produce timepiece parts using machines guaranteeing precision and facilitating exchangeability. These technical breakthroughs forged the reputation of the Grande Maison in the Vallée de Joux that soon became known for the quality and sturdiness of its calibres. This feat naturally gave wings to the two entrepreneurs. Through close cooperation between the workshops of Jacques- David LeCoultre and Edmond Jaeger, a number of models exuding a rare blend of elegance and refinement were produced. The alliance between Swiss precision and Parisian luxury intensified and proved so successful that, less than 20 years later, the brand became known under the double-barrelled name of Jaeger-LeCoultre.

This extraordinary combination of audacity, prestige and proven precision continued throughout the 20th century and asserted itself with renewed and self-evident strength in the early years of the new millennium with the introduction of the Master Ultra Thin line.

The extra-slim pink gold case of the Master Ultra Thin 1907 watch is shaped like a knife-blade, a design that ensures en even thinner profile. The engineers and watchmakers of the Manufacture meticulously studied each movement component and each case element in order to save precious millimetres at each stage of production. Nonetheless, at no stage does this asceticism compromise beauty. Loyal to its history of which one part was written in the City of Light and the other in the splendid isolation of the Vallée de Joux, the Manufacture well knows that the watchmaking art represents both a technical and an aesthetic accomplishment. The minimalist philosophy behind the Master Ultra Thin 1907 watch is thus expressed in a 39 mm-diameter case designed to smoothly embrace the curve of any wrist. This relatively modest size required the Jaeger-LeCoultre specialists to achieve even greater feats in designing and building a Fine Watchmaking movement able to fit within such a comparatively small case.

Elegance and technical feats
Manually-wound Jaeger-LeCoultre Calibre 849 is a marvel of finesse entirely crafted, assembled and decorated by hand in the complications workshop of the Manufacture. It comprises 123 parts, has a 35-hour power reserve and is equipped with a balance steadily beating at the frequency of 21,600 vibrations per hour. In keeping with grand watchmaking traditions, it also displays the hours and minutes by central hands with the legendary precision of Jaeger- LeCoultre movements, despite measuring just 1.85 mm thin.  

The dial of the watch is the aesthetic embodiment of this horological minimalism. Two dauphine-type hands sweep smoothly over the grained white dial punctuated by baton-type hour-markers that are doubled at 3, 6 and 9 o’clock. The minutes dots between two hour- markers are dusted with pink gold, while the Jaeger-LeCoultre signature topped by the JL logo appears at 12 o’clock. After a slow and gentle process of maturation, horological essentials are thus expressed in a few concise lines – a privilege that remains the exclusive preserve of true masters. The Master Ultra Thin 1907 watch comes with an alligator leather strap secured by an 18-carat pink gold pin buckle.

Master Ultra Thin Grand Feu
Driven by the same ultra-slim movement, the Master Ultra Thin Grand Feu watch is the interpretation of the Master Ultra Thin 1907 intended for keen enthusiasts wishing to encircle their wrist with a timepiece featuring a white gold dial that illustrates one of the traditional skills passionately cultivated by the Grande Maison. Few indeed are the artisans still capable of mastering the Grand Feu enamelling technique, which involves firing the watch face meticulously coated with successive layers of enamel at very high temperatures generally ranging from 800 to 900 degrees Celsius. This extreme heat entails the danger of irrevocably ruining the work in progress, since only a reliable sense of instinct and longstanding experience can enable the artisan to determine the exact moment when the gold dial disc should be removed from the kiln. The case of the Master Ultra Thin Grand Feu, also crafted from white gold, features the same blade-shaped profile, although its thickness has been marginally increased to 5.04 millimetres in order to accommodate beneath the sapphire crystal the various enamel layers applied to the timelessly elegant dial. The latter bears the inscription “Email Grand Feu” appearing between the 7 and 8 o’clock numerals. This time-honoured handcrafted technique ensures that the watch is an authentic work of art that will for centuries maintain the same immutable initial appearance and radiance.
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Master Ultra Thin 1907 and Master Ultra Thin Grand Feu
  • Q129 25 20, Master  Ultra Thin1907
  • Q129 35 E1, Master Ultra Thin Grand Feu   


  • Mechanical manually-wound movement, Jaeger-LeCoultre Calibre 849, crafted assembled and decorated by hand
  • 35-hour power reserve
  • 21,600 vibrations per hour
  • 123 parts  
  • 19 jewels
  • 1.85 mm thin  


  • Master Ultra Thin 1907: white, grained, hour-markers and traditional minute circle
  • Master Ultra Thin Grand Feu: white Grand Feu enamel, hour-markers and traditional minute circle  


  • Dauphine-type for the Master Ultra Thin 1907
  • Rhodiumed leaf-type for the Master Ultra Thin Grand Feu  


  • Hours and minutes  


  • Master Ultra Thin 1907: 18-carat pink gold, 4.05 mm thin
  • Master Ultra Thin Grand Feu: 18-carat white gold, 5.04 mm thin
  • 39 mm in diameter
  • Polished finish
  • Water resistance: 3 atm  


  • Master Ultra Thin1907: alligator leather, 18-carat pink gold pin buckle
  • Master Ultra Thin Grand Feu: alligator leather, 18-carat white gold pin buckle