Over the century or so that wristwatches have been the norm in watchmaking, few, if any, timepieces have had the longevity and staying power of the Jaeger-LeCoultre Reverso. The Reverso line has been in continuous production since 1931, and to celebrate its 90th anniversary this year, the brand has devised a wide range of variants, updates, and special editions. The crown jewel of these, however, is undoubtedly the new Reverso Hybris Mechanica Calibre 185. Bringing together a dream team of high-end complications with multiple world firsts, including the first-ever four-faced wristwatch and perhaps the most comprehensive mechanical indicator of lunar cycles ever devised, into a truly wearable package, the new limited-edition Jaeger-LeCoultre Reverso Hybris Mechanica Calibre 185 may well be an atom bomb in the current haute horlogerie arms race.

While many designs packing in 11 complications tend to bloat to oversized proportions, the white-gold case of the Jaeger-LeCoultre Reverso Hybris Mechanica Calibre 185 remains relatively compact and wearable. Measuring in at 51.2mm by 31mm with a 15.15mm overall thickness, the watch is on the larger side for a Reverso, but it should likely be far from an ungainly showpiece on the wrist. The overall case design is classic Reverso, with the Art Deco streamlined grooves at 12 o’clock and 6 o’clock highlighting the rotating mid-case against its outer frame.

Jaeger-LeCoultre claims the Reverso Hybris Mechanica Calibre 185 is the world’s first wristwatch with four faces. This arrangement allows the 11 complications to spread out visually, leaving each dial with a distinctive but legible layout. The primary dial is a semi-skeleton arrangement, integrating the Reverso’s traditional blued sword hands and chemin de fer minutes track on top of a series of clous de Paris guilloché bridges. This familiar dial layout also integrates a perpetual calendar display, with the sunburst finished month, day, and 5 o’clock big date wheels on full display. Naturally, the oversized flying tourbillon at 7 o’clock dominates the scene here, with its blued screws and propeller-style running-seconds indicator. While this bold and complex element takes center stage on the main dial, this dial also adds a small day/night indicator and leap year indicator at 10 o’clock and 2 o’clock, respectively.

The second dial of the Jaeger-LeCoultre Reverso Hybris Mechanica Calibre 185 takes up the traditional Reverso second dial slot on the opposite side of the rotating mid-case and keeps things somewhat simpler, visually. Timekeeping functions are handled by a jump hour display flanked by a miniature red arrow minute hand, leaving most of the visual real estate open for the intricate mechanisms of the minute repeater complication. Activated by the lever flanking the main crown, this chiming function is the first of its kind to deliver a completely seamless transition between strikes for the hours, quarter hours, and minutes. While traditional minute repeaters pause momentarily while switching between the hours, quarters, and minutes tones due to the pivoting rack and cam system employed, the new advancements debuted in the Hybris Mechanica Calibre 185 eliminate these gaps entirely. However, Jaeger-LeCoultre is decidedly vague on the mechanical details surrounding this breakthrough.

Since the third dial of the Jaeger-LeCoultre Reverso Hybris Mechanica Calibre 185 is located on the cradle portion of the case, beneath the Reverso’s signature rotating case assembly, the natural assumption to make is that the watch uses two independent movements. However, this is only partly true. While there is a gear train embedded within the case cradle that handles the functions of the third and fourth dials, this directly connects to the main movement each day at midnight via an extending connector pin which corrects the displays on each of those dials. Outside of that once-a-day correction, the gear train remains inert, without its own power source or regulation. It’s an undeniably complex system, but one that allows the case cradle to remain extremely slim so as not to disrupt the lines of the traditional Reverso case. This third dial uses several patented mechanisms to create one of the most comprehensive moonphase displays ever fitted to a mechanical wristwatch. While a traditional moonphase complication tracks the synodic cycle, or the progress of the moon from full moon to new moon and back each month, the Reverso Hybris Mechanica Calibre 185 adds two additional lunar trackers for the draconic cycle and the anomalistic cycle of the moon.

The largest display at 12 o’clock handles the classic synodic cycle for the Northern Hemisphere with a laser-etched moon disc covered by a moving hand-lacquered disc in blue and decorated with fine gold dust. The other two subdials are somewhat more esoteric. At 8 o’clock is the indicator for the draconic cycle. The draconic cycle tracks the path of the moon as it interacts with the path of the Earth around the sun, meaning this display can be used to track the occurrence of solar and lunar eclipses. Lastly, the 4 o’clock subdial is dominated by a micro-enameled rendering of the Earth, surrounded by a representation of the moon in an elliptical orbit. This tracks the anomalistic cycle, which measures the distance between the Earth and the moon at various points in its orbit. This interplay can affect the apparent size of the moon in the sky by up to 14 percent, and also plays an important role in the cycle of ocean tides. Jaeger-LeCoultre has patented the indicators for both the draconic and anomalistic lunar cycles, making this the only wristwatch ever to include this group of astronomical complications. Beyond the complexity of this set of moonphase complications, this comprehensive astronomical suite is also exceedingly accurate, with Jaeger-LeCoultre claiming the moonphase display only needs adjustment once every 1,111 years.

Lastly, the true caseback of the Reverso Hybris Mechanica Calibre 185 is given over to the fourth dial. Here, there is only one complication, a traditional pink gold moonphase display for the Southern Hemisphere, but the rest of the caseback is richly decorated with star charts of the Southern Hemisphere. Intricately finished in blue lacquer and hand-engraved, it may lack the technical complexity of the other three but still presents a visual spectacle.

The in-house Calibre 185 hand-wound movement inside the Jaeger-LeCoultre Reverso Hybris Mechanica Calibre 185 is a dauntingly complex piece of engineering. Sporting 97 jewels and an untold number of components, this movement offers 11 complications across its four displays, while providing a fairly average 50-hour power reserve at a 28,800 bph beat rate. As the person who can afford a piece like this is likely to have and rotate through a sizeable collection of timepieces, this begs the question of what happens when that 50-hour reserve winds down. With many high complication watches, resetting all functions after a period of dormancy can be an extremely complex task, but Jaeger-LeCoultre plans for this with the Calibre 185. The watch is delivered in a bespoke presentation box that includes an automated winding and setting mechanism for each of the Calibre 185’s functions. To reset the watch after a period of disuse, the wearer operates a two-position crown on the side of the display box, first selecting how many days have passed since the last time the watch was worn. After that is input, the crown can be pulled out to the second position and wound like a normal crown, which automatically both winds the movement and correctly sets each of the 11 complications. Jaeger-LeCoultre completes the Reverso Hybris Mechanica Calibre 185’s commitment to wearability with a traditional midnight blue alligator leather strap.

Beyond the sheer complexity of its movement, its four dials, and its patented new complications, the limited edition Jaeger-LeCoultre Reverso Hybris Mechanica Calibre 185 stands out in the ultra-high-end realm of haute horlogerie for its usable nature. Despite the dizzying array of displays and functions, this is a normally proportioned, legible, and relatively easy-to-set wristwatch. This is a watch that potentially transcends the wearable modern art showcases common to this segment to become genuinely feasible as a timepiece in the real world. Only 10 examples of the Jaeger-LeCoultre Reverso Hybris Mechanica Calibre 185 will be made, available to order now through authorized dealers at an astronomical MSRP of €1.35 million. For more information, please visit the brand’s website.