The Jaeger-LeCoultre Master Ultra Thin Squelette stands as one of the most important milestones in the history of
ultra-thin skeleton watchmaking. Released in 2015, this extraordinary creation was not only the
thinnest ladies’ watch ever produced by Jaeger-LeCoultre at that time, but also claimed the title of the
world’s thinnest fully mechanical wristwatch, surpassing the Piaget Altiplano 900P by just 0.05mm.
With a case thickness of only 3.6mm, the Jaeger-LeCoultre Master Ultra Thin Squelette represents the absolute limit of traditional mechanical engineering.
This level of thinness required extensive redesign of both the movement structure and the case architecture, demonstrating why Jaeger-LeCoultre is widely recognized as the
“Watchmaker of Watchmakers”.
(Official Jaeger-LeCoultre Website)
Its ultra-slim profile allows the watch to sit gracefully on the wrist, giving it both a refined presence and exceptional comfort.
For collectors and enthusiasts of ultra-thin watches, the Master Ultra Thin Squelette represents a perfect union of
technical brilliance and artistic expression.
Visually, the Jaeger-LeCoultre Master Ultra Thin Squelette is defined by its beautifully skeletonized dial.
To maintain both legibility and visual harmony despite the openworked design, Jaeger-LeCoultre divided the outer dial into
12 individual hour sections. These are decorated with either fine grand feu enamel or luminous
mother-of-pearl, creating a contrast against the exposed movement below.
The intricate openwork allows light to penetrate through the dial, revealing the
depth of the mechanical structure and emphasizing the craftsmanship behind this ultra-thin skeleton watch.
Each component is carefully hand-finished to preserve both strength and beauty at an incredibly reduced thickness.
Powering the watch is the ultra-flat hand-wound Caliber 849ASQ, measuring only 1.85mm thick.
This movement is a skeletonized evolution of the legendary Caliber 849, one of the thinnest movements ever made by Jaeger-LeCoultre.
Collectors can even observe the mainspring tension indicator at the 1 o’clock position, a rare detail in ultra-thin watchmaking.
Despite its extreme thin profile, the Jaeger-LeCoultre Master Ultra Thin Squelette offers a
33-hour power reserve. While slightly shorter than the 48 hours of the Piaget 900P, this compromise is essential
to achieve such remarkable thinness without sacrificing mechanical stability.
For comparison, you can explore Piaget’s ultra-thin achievements here:
Piaget Official Website.
The watch was launched in three highly exclusive versions, each strictly limited to
100 pieces worldwide:
- Red enamel dial with rose gold case
- Blue enamel dial with white gold case
- Mother-of-pearl dial with white gold case
Each version showcases a different artistic personality, making the Jaeger-LeCoultre Master Ultra Thin Squelette
a highly sought-after collector’s piece in the world of haute horlogerie.
Jaeger-LeCoultre Master Ultra Thin Squelette Specifications
Case: White gold / Rose gold
Diameter: 38mm
Thickness: 3.6mm
Crystal: Sapphire front and back
Dial: Skeletonized with enamel / mother-of-pearl markers
Movement: Hand-wound Caliber 849ASQ
Power Reserve: 33 hours
Strap: Alligator leather strap
Buckle: White gold / Rose gold buckle
Water Resistance: 30 meters
