Jaeger-LeCoultre Master Ultra Thin Date automatic silver dial alligator leather strap 39 mm

Watchmaking Refinement for Today’s Aesthetes

Born from Jaeger-LeCoultre’s extraordinary legacy in the field of ultra-thin timepieces – whose first creations appeared at the dawn of the 20th century – the Master Ultra Thin collection embodies the very essence of contemporary horological elegance.
With its clean lines, polished surfaces, and gracefully curved lugs, its design expresses a modern classicism in which every detail is conceived to enhance the purity of form.

Created for today’s aesthetes, the Master Ultra Thin perfectly captures both the timeless sobriety and technical mastery that define the Grande Maison. It highlights nearly two centuries of mechanical expertise and continuous innovation, the fruit of the unique savoir-faire cultivated within the Manufacture in Le Sentier.
Beneath its apparent simplicity lies the precision and horological sensitivity that are hallmarks of Jaeger-LeCoultre, where the pursuit of perfect balance remains an inimitable signature.

A Luminous Interpretation of Timeless Design

With its sunray-brushed silver dial, the Master Ultra Thin Date Q1238421 embodies the purity and symmetry so dear to Jaeger-LeCoultre.
Every detail of the dial is conceived as an exercise in balance: the date window at 6 o’clock anchors the composition, while the elongated trapezoidal hour markers and Dauphine hands — polished on one side and satin-brushed on the other — catch the light to create a subtle and lively interplay of reflections.

This luminous face finds its setting in a polished 39 mm stainless-steel case, whose slim profile and gentle curves naturally follow the wrist’s contour.
Elegant without ostentation, the piece evokes modernity through restraint — a timeless design where the purity of form takes precedence over visual complexity.

Presented on a black alligator leather strap secured by a folding clasp, the Q1238421 stands out for its balanced proportions and understated charm.
A watch that is both contemporary and classic, faithful to the philosophy of the collection: elegance in simplicity, perfection in proportion.

An Exceptional Mechanism Revealed Beneath Sapphire

At the heart of the Master Ultra Thin Date Q1238421 beats the Jaeger-LeCoultre Calibre 899, an ultra-thin automatic movement designed and assembled entirely within the Manufacture in Le Sentier.
Visible through the transparent sapphire caseback, it reveals the full beauty of the Maison’s artisanal craftsmanship: hand-chamfered bridges, blued screws, Geneva stripes, and perlage on the mainplate.

This extra-flat calibre, the result of decades of expertise, offers a 70-hour power reserve and guarantees outstanding precision while maintaining an exceptionally slim profile.
Before leaving the Manufacture, each watch undergoes Jaeger-LeCoultre’s rigorous 1,000-Hour Control, a unique in-house testing protocol that certifies the reliability, resistance, and chronometric stability of every creation.

Through this visible mechanism, the Master Ultra Thin Date expresses everything that makes Jaeger-LeCoultre unique: total technical mastery, an acute sense of detail, and effortless elegance.
A timepiece designed to stand the test of time — in every sense of the word.