Have you missed the Jaeger-LeCoultre Duomètre or forgotten about it? I’m certainly in the former camp, as it was a real tour de force from Le Sentier when it debuted in 2007. It split its power supply into two streams, one barrel and going train for the time and a separate set for the complication(s), hence the name: Duomètre. For 2024, the brand finally directed its attention and efforts to this somewhat ignored collection, and part of that refresh is this new Jaeger-LeCoultre Duomètre Quantième Lunaire watch.

Inspired by the double-barrel-equipped Calibre 19/20RMSMI from 1881 — fitted to a pocket watch, of course — every modern Duomètre has brilliantly displayed its duality on the dial with a regular time subdial at 2 o’clock, one or more additional complications at 10 (at times flipped), and a foudroyant seconds display above 6, flanked by two power reserve indications, perhaps the biggest giveaway of the two independent power sources.

At 42.5mm wide and 13.05mm thick, 2024’s stainless steel Jaeger-LeCoultre Duomètre Quantième Lunaire watch features the new Duomètre case. It is inspired, again, by 19th-century pocket watches, the savonette variant, to be precise, and their rounded, disc of soap-like contours. It still looks round to me, although a lot more filigree, thanks, in part, to the hollowed-out lug and case profiles. You could argue that the bezel is a bit more delicately rounded. Compare this new piece to the old Duomètre Quantième Lunaire and you’ll see how much more drastic the original’s exterior version was. The openworked power reserve displays return on other 2024 versions of the Duomètre, just not on this one.

The Jaeger-LeCoultre Duomètre Quantième Lunaire watch is powered by the hand-wound Jaeger-LeCoultre Calibre 381 with the following functions: Hours, minutes, central seconds, 1/6th of a second, moon phases, date, two power reserves — which, mind you, is 50 hours for each barrel. The barrels use pocket watch-style ratchet clicks where you have to turn the crown backward as well as forward to wind one barrel or the other.

Jaeger-LeCoultre claims that the foudroyant hand, which whirls continuously in a sub-dial at 6 o’clock, is “emphasizing the precision of the calibre.” While the presentation mentions the word “precision” 8 times, there is no mention of the actual time-keeping performance tolerances Jaeger-LeCoultre tests these watches for. We couldn’t find any relevant information on this on Jaeger-LeCoultre’s website, either, not under the current Duomètre product pages, or where the brand would discuss its 1,000 Hour Control testing. With Rolex doing -2/+2, Omega now 0/+2 with Spirate™, Master Chronometers at 0/+5, Jaeger-LeCoultre should get with the times — saying you are accurate because your movement is complicated might have worked with watch buyers of the 2000s, but there is a reason why the aforementioned have invested heavily into narrowing their accuracy tolerance window.

Beautifully made and yet more refined than its predecessor, the new Jaeger-LeCoultre Duomètre Quantième Lunaire watch is available with a deep blue dial with a variety of decorative finishes, a new and all-round improved case, and a stunning movement that Jaeger-LeCoultre doesn’t say just how high-performing it actually is. The new Jaeger-LeCoultre Duomètre Quantième Lunaire watch is priced at $44,300 USD. You can learn more at the brand’s website.