2022 Jaeger-LeCoultre Master Ultra Thin Réserve de Marche (Ref. Q1378420 / 176.8.38.S)

History and Significance

The Jaeger-LeCoultre Master Ultra Thin collection is built around a particularly difficult idea to execute well: adding mechanical complexity without sacrificing the elegance of a traditional dress watch. The reference Q1378420 manages that balance through a dial displaying the date, small seconds, and power reserve while still maintaining a remarkably clean overall appearance. Each indication occupies its own portion of the dial, preventing the complications from competing with one another visually. The result feels distinctly mechanical without becoming unnecessarily busy.

The power-reserve display is especially appropriate for a watch from Jaeger-LeCoultre. Rather than existing purely as decoration, it provides an immediate indication of the energy remaining in the automatic movement and introduces subtle asymmetry to the dial. A pointer date occupies the opposite side, while the small-seconds register anchors the lower portion of the layout. Together, those three displays give the reference Q1378420 significantly more visual depth than a conventional three-hand dress watch.

At 39mm, the stainless steel case gives the watch contemporary proportions while retaining the slim profile expected from the Master Ultra Thin family. Long, gently curved lugs extend the watch naturally across the wrist, and the narrow bezel leaves a generous amount of space for the dial. Turning the watch over reveals an exhibition caseback, allowing the automatic movement and its finishing to become part of the experience. That combination of restrained design from the front and visible mechanics from the back captures much of what makes Jaeger-LeCoultre compelling as a manufacture.

The watch dates to 2022 and remains accompanied by its complete original box and paperwork. A new HC leather strap has been fitted for wear, while the original Jaeger-LeCoultre deployant clasp remains with the watch. Those details make the package particularly complete while allowing the watch to be worn without placing additional use on an older strap. The reference Q1378420 ultimately offers considerably more mechanical interest than its understated appearance initially suggests.

Writer's Thoughts

Limited editions become far more interesting when the limitation has an actual reason 

Complicated dress watches can easily become too crowded, but the reference Q1378420 avoids that problem remarkably well. The power reserve, pointer date, and small seconds each add something useful to the dial while leaving enough negative space for the design to remain elegant. The 39mm case gives the complications room to breathe, and the thin construction prevents that larger diameter from feeling heavy or overly sporty. The exhibition caseback also matters on a watch like this because the mechanical side of Jaeger-LeCoultre is such an important part of the appeal.

The complete 2022 set makes this particular example especially appealing as a modern watch that still follows traditional dress-watch principles. The new HC leather strap keeps the presentation fresh, while the original Jaeger-LeCoultre deployant maintains the correct factory hardware. There is enough complication to make the watch interesting during regular wear without sacrificing the restraint that defines the Master Ultra Thin collection. For a modern Jaeger-LeCoultre, the balance between mechanical interest, wearable proportions, and understated design is particularly strong.

Our Promise

Every watch is thoroughly vetted, carefully described with complete transparency, and guaranteed authentic. Each piece is offered in honest condition, ensuring collectors receive a timepiece that reflects both originality and integrity.

Brand: Jaeger-LeCoultre

Model: Master Ultra Thin Réserve de Marche

Reference: Q1378420 / 176.8.38.S

Year: 2022

Case Material: Stainless steel

Case Size: 39mm

Dial: Silver dial with power reserve, pointer date, and small seconds

Movement: Automatic

Strap/Bracelet: New HC leather strap

Buckle/Clasp: Original Jaeger-LeCoultre deployant clasp

Contents: Complete set with original box and paperwork