Monochrome Watches
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Pre SIHH 2012 – Jaeger-LeCoultre Duomètre à Quantième Lunaire 40.5

| By Frank Geelen | 2 min read |

In 2010 Jaege-LeCoultre introduced the Duomètre à Quantième Luniare, which became immediately populair amongst watch fans and it was even chosen as Timezone Watch of the Year 2010. Now Jaeger-LeCoultre releases a new version…

It’s called the Duomètre à Quantème Luniare 40.5. From its name (and specifications) we can conclude it now comes in a more elegant size. The previous model was 42 mm in diameter and the new one is 40.5 mm. Is Jaeger-LeCoultre setting the trend for down-sizing? And what more did they change on this new Duomètre?

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First and foremost I think it’s good to take note that JLC already started with down-sizing with 2011 novelties like the Master Geographic and the Master Ultra Thin (MUT) Moon. Many watch fans, aficionados and collectors have been longing for the moment the trend of ‘big, bigger, biggest’ would take its turn. Would this trend proceed now JLC, again, down-sizes an existing model? I sure hope so!

Something else significantly changed on the Duomètre à Quantième Lunaire 40.5 in comparisson to the previous model and that’s the dial. On the previous model the lower part of the dial was open and parts of the movement could be seen.  The closed dial, similar to the Duomètre à Chronographe, was first introduced on the to 200 pieces limited white gold with black dial version.

The jumping foudroyante seconds hand, at the 6 o’clock position, shows 1/6th of a second increments. At the right side of the dial we find the hour/minutes and to the left we can see the date and moon phases for both hemispheres together in one sub-dial.

Inside ticks caliber 381, so that remained unchanged. The so-called ‘dual-wing’ movement features two independent power supplies. One of them is regulated by the escapement and balance; the other for the time, date and age of the moon displays. The coupling is done via the jumping seconds at 6 o’clock so both gear trains don’t unwind at their own pase.

Each side or ‘wing’ of the movement has its own barrel with a power reserve of 50 hours. Both springs are wound through the crown: rotating it clockwise winds the timing barrel (escapment); turning the crown counter-clockwise winds the power reserve for the functions (hour, minute, seconds, jumping seconds, date, moon phase). Setting the time is also done via the crown and the pusher at 10 o’clock is to adjust the date. The moon phase can be adjusted via a corrector in the side of the case.

Here are the specifications: Mechanical manually-wound Jaeger-LeCoultre Calibre 381, crafted, assembled and decorated by hand

  • 21,600 vibrations per hour
  • 50-hour power reserve
  • 367 parts
  • 40 jewels
  • 7.25 mm thick
  • 33.70 mm in diameter
  • Two independent barrels


  • ø 40.5 mm and 13.07 mm in height
  • 18-carat pink gold, polished and satin-brushed finish
  • sapphire crystal, cambered on the dial side, hardness no. 9, glareproofed on front and back

The price of the new Jaeger-LeCoultre Duomètre à Qunatième Luniare 40.5 will be € 29.000 Euro including taxes.

More information can be found at the Jaeger-LeCoultre website.

2 responses

  1. I think the Asian market is setting the trend for down-sizing. Still, I find it very welcome. If I’m spending upwards of 6k on a dress watch, I want it to be relatively timeless. 42-44mm is suitable for some sport watches, but simply too big for dressier watches.

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