Jaeger-LeCoultre Revisits the Master Ultra Thin Power Reserve

Marrying aesthetic sophistication with mechanical virtuosity, the Master Ultra Thin collection is a stunning example for Jaeger-LeCoultre’s philosophy of watchmaking. In 2024, the collection is enriched by a new interpretation of the Master Ultra Thin Power Reserve. The elegant dress watch features a subtly modernized case (39.0 x 8.95mm), a new gradient midnight blue sunray dial, and an increased power reserve thanks to an updated movement.

The watchmakers of the Grande Maison have revised the self-winding Caliber 938 to power a new generation of timepieces. Most notably, the power reserve has been increased to 70 hours – long enough to leave the watch aside for an entire weekend and wear it again on Monday with no need to rewind it or reset the time. This significant gain in power reserve has been achieved without adding to the height of the caliber, which remains 4.9mm thick. The mainspring barrel was redesigned, some key components are now made of silicon, which makes energy transmission smoother by reducing friction of the moving parts, and other minor changes have been made to increase the reliability. The high degree of the finishing has remained the same, though. The exhibition case back displays Geneva stripes, blued screws, perlage, and a partially skeletonized oscillating with.

The power reserve function is a signature complication of Jaeger-LeCoultre, pioneered by the manufacture in 1948 with the introduction of Caliber 481. The Powermatic, distinguished by its distinctive red-and-white indicator, was the world’s first self-winding timepiece with a power reserve gauge and quickly became a key model for the manufacture in the early 1950s. The Master Ultra Thin Power Reserve is equally recognizable, with the distinctive design of the power reserve display complemented by date and small seconds indicators 

The architecture of the watch face has also been refined. While retaining all the symmetry and balance of the earlier dial layout, larger sub-dials highlight the complications, making the date, power reserve and small seconds displays even more legible than before.

This is amplified by the newly elongated shape of the applied hour markers, and the use of a different finish (polished and satin) on each facet of the Dauphine hands, and the use of transferred golden dots to mark the minutes track. Matching the colour of the pink gold case, these elements create aesthetic harmony while contrasting dramatically with the gradient midnight blue of the sunray dial. The subtle matt texture of the sub-dials adds visual depth and richness.

The Jaeger-LeCoultre Master Ultra Thin Power Reserve is presented on a navy-blue alligator strap.Pricing is marked at $21,200.

To learn more, visit Jaeger-LeCoultre, here.