Jaeger-LeCoultre's "Master Ultra Thin" collection welcomes the new "Master Ultra Thin Tourbillon Moon," which incorporates a tourbillon, a jumping date for enhanced legibility, and a moon phase display for both hemispheres. This is an elegant timepiece that carries on the manufacture's advanced craftsmanship and design codes.

The "Master Ultra Thin" collection from Jaeger-LeCoultre symbolizes the manufacture's philosophy of merging advanced craftsmanship with timeless beauty. In 2020, this collection was further enriched with the introduction of the new "Master Ultra Thin Tourbillon Moon."

This model features Jaeger-LeCoultre's signature peripheral "jumping" date, along with the rare combination of a moon phase and a tourbillon, a first for Jaeger-LeCoultre's long history. This pairing is made possible by the new automatic Calibre 983.

The tourbillon was developed in the early 19th century to counteract the effects of gravity on a watch's escapement. While it improved accuracy, the tourbillon was largely forgotten with the shift from pocket watches to wristwatches in the 20th century. However, in 1946, as part of its research into improving accuracy, Jaeger-LeCoultre developed Calibre 170, a movement equipped with a tourbillon. This movement, housed in a pocket watch, was originally developed for chronometer certification, winning the accuracy competition commemorating the 100th anniversary of the Neuchâtel Observatory in 1948, and receiving several more accolades in the 1950s. Then, in 1993, when tourbillon-equipped wristwatches were still extremely rare, Jaeger-LeCoultre produced its first model, the "Reverso," featuring Calibre 828. Further research led to the development of the "Master Gyrotourbillon 1" in 2004, the first spherical multi-axis tourbillon.

In 2009, the "Master Tourbillon" was unveiled, powered by Calibre 978. This watch won an award at the International Chronometer Contest organized by the Le Locle Watch Museum in Switzerland, and since then, this calibre has become Jaeger-LeCoultre's primary tourbillon movement. Furthermore, it underwent significant revisions in 2019, receiving a new, top-tier finish.

Jaeger-LeCoultre's engineers developed the new Calibre 983 based on this Calibre 978, subsequently adding two complications: the "jumping" date and the moon phase. This new calibre, featured in the present model, also includes the triple moon phase display announced in 2019, showing the lunar phase for both hemispheres, and a 45-hour power reserve.

The case of this model is crafted from Grand Rose® gold, a new pink gold alloy. Introduced in 2020, this material is characterized by its exquisite luster and deep hue, while also possessing exceptional resistance to fading over time. The case, which adheres to the classic and elegant design codes of the "Master Ultra Thin," features a full polish finish, with finely chamfered, elongated lugs harmonizing beautifully with the bezel.

The dial color is eggshell white, which enhances the warmth of the pink gold. Against this understated backdrop, the moon phase display and tourbillon are positioned, accentuating the refined aesthetic. Furthermore, the Dauphine hands perfectly complement the elongated arrow shape of the gold-finished applied indices. The indices vary in shape, designed to match their position on the dial. Several key indications are highlighted in red, enhancing legibility while adding a subtle accent.

The complex moon phase mechanism at 12 o'clock, mimicking celestial bodies, displays the lunar phase for the Northern Hemisphere. Against a deep blue sky sprinkled with stars, a polished gold disc is set. Surrounding this sky is a ring featuring the Southern Hemisphere's lunar phase on the left and the age of the moon on the right, both indicated by hands of identical shape at their tips. The date display on the periphery utilizes Jaeger-LeCoultre's signature "jumping" date mechanism. To ensure the date hand does not obstruct the tourbillon, it jumps 90 degrees when changing from the 15th to the 16th of the month.

At 6 o'clock lies the tourbillon, the star of this watch. The newly designed bridge is made of polished pink gold, and the titanium tourbillon cage (weighing approximately 0.3 grams including its components) rotates once every 60 seconds. The precise tourbillon bridge and the wide, small window maximize transparency and brightness, highlighting the allure of this mechanism.

On the reverse side, the openworked tourbillon bridge is elongated, further enhancing transparency, while the Côtes de Genève decoration beautifully accentuates the sunray-patterned stripes on the mainplate. The openworked pink gold winding rotor, adorned with the JL logo and featuring a combination of polished and micro-blasted surfaces, allows a clear view of the movement, which boasts additional beautiful finishes such as blue screws, circular graining (perlage), and chamfered bridges.

Like all Jaeger-LeCoultre timepieces, this "Master Ultra Thin Tourbillon Moon" comes with an 8-year warranty and has obtained the 1000 Hour Control certification, one of the most stringent in the watch industry.