Jaeger-LeCoultre Master Ultra Thin Moon 36mm Returns in Pink Gold
The Jaeger-LeCoultre Master Ultra Thin Moon 36mm is back in 18k pink gold. Reference Q1242521 pairs a 36mm, 9.3mm-thick polished case with the in-house Calibre 925, a self-winding movement with a 70-hour power reserve. It joins the permanent collection, is reported as available now, and costs US$23,100 (EUR 23,900, CHF 19,800). Monochrome and Luxe Digital put that at about EUR 4,500 below the 39mm gold editions of the same watch.
At a glance
| Detail | Specification |
|---|---|
| Reference | Q1242521 |
| Case | 18k pink gold, 36mm diameter, 9.3mm thick, polished, sapphire crystals front and back |
| Dial | Silvered, sunray-brushed; gold-coloured faceted trapezoidal markers, Dauphine hands; moon phase and pointer date at 6 o'clock |
| Movement | In-house Calibre 925, self-winding, 4Hz, 30 jewels, 245 components, 4.9mm thick |
| Power reserve | 70 hours |
| Water resistance | 50m (5 bar) |
| Strap | Black alligator, quick-release, with interchangeable 18k pink gold pin buckle |
| Production run | Permanent collection; no limit stated |
| Price | US$23,100 (EUR 23,900; CHF 19,800) |
| Availability | Reported available now |
Design: the Jaeger-LeCoultre Master Ultra Thin Moon 36mm case and dial
The case is 18k pink gold, polished on every surface, with a smooth bezel and long, curving lugs. At 36mm across and 9.3mm thick it sits at a conventional dress-watch size. Sapphire crystals cover both sides, and the see-through caseback is secured by screws. Water resistance is 50 metres, which suits a dress watch worn with care rather than in the water.
The dial is silvered with a sunray finish. Gold-coloured faceted trapezoidal hour markers are applied, a pearl-like minute track frames the edge, and Dauphine hands do the telling. At 6 o'clock the moon phase and a pointer date share one sub-dial, and there is no hour marker in that position. Haute Time and The Hour Markers describe the moon disc as golden against a deep blue, star-studded background, with the date on a ring read by a thin hand. Monochrome notes that the smaller case places this sub-dial closer to the edge of the dial than on the 39mm versions.
Movement: Calibre 925 with a 70-hour reserve
Inside is the in-house Calibre 925, the same movement the 39mm version uses. It is self-winding, runs at 4Hz (28,800 vibrations per hour), and is 4.9mm thick, which is what keeps the 9.3mm case slim. Element in Time lists 30 jewels, 245 components and a single barrel. The power reserve is 70 hours, so the watch keeps running through a weekend off the wrist.
The finishing is visible through the sapphire caseback: Côtes de Genève, bevelled bridges and blue screws, with an open-worked 22k pink gold rotor carrying the JL logo. Haute Time says the calibre is designed, made and assembled at the Manufacture in Le Sentier. Functions are hours, minutes, seconds, a pointer date and the moon phase. The Manual reported in 2023, on a different Moon model, that Calibre 925's reserve had risen to 70 hours from 38 on earlier generations of the calibre.
Because the movement is only 4.9mm thick, the open-worked rotor and the polished bridges are the main thing seen from the back. Element in Time lists the crown at 3 o'clock. The date is read by a hand rather than through a window, so the dial stays free of a cut-out.
What changes from the 39mm Moon and the 36mm steel
Monochrome and Luxe Digital both say the Master Ultra Thin Moon lived almost entirely in 39mm cases for years. A 36mm steel version arrived a couple of years ago, and this pink gold model follows it in the same size. The movement is unchanged from the 39mm watch, so the difference is the wearing experience: a smaller diameter, a more traditional dress-watch proportion, and a moon and date sub-dial that sits nearer the dial's edge. Haute Time and Mr Watchmaster say the proportions pay tribute to 1950s round wristwatches.
Luxe Digital headlines the release as the Moon coming back in 36mm pink gold. The other outlets we read describe it as following the steel 36mm, and we could not confirm an earlier 36mm pink gold reference from a brand source, so treat the "return" as a reading of the range rather than an official statement. The brand's own product pages returned errors when we tried them, and we found no press release, so every specification here comes from the outlets named below.
Price and availability of the Master Ultra Thin Moon 36mm
Monochrome lists EUR 23,900, CHF 19,800 and US$23,100. Haute Time and Element in Time both give US$23,100, and Mr Watchmaster gives a UK recommended price of GBP 20,700. Monochrome and Luxe Digital say that is about EUR 4,500 less than the 39mm gold editions, which implies roughly EUR 28,400 for those, a figure neither outlet states directly. Because the watch is part of the permanent collection, no production limit has been announced, and availability is described as immediate.
For context, The Manual reported a pink gold Moon with a midnight blue dial, a different watch, at $23,000 in October 2023. Gold prices have been a theme this year, which our report on gold prices and luxury watches covers. Prices are indicative and vary by market and retailer.
Who is it for? On the evidence of the specifications, it suits a buyer who wants a slim gold dress watch with a moon phase, a 70-hour reserve and a visible, finished movement, and who prefers a smaller case than the 39mm versions. The black alligator strap is quick-release and fitted with an interchangeable 18k pink gold pin buckle, so the strap and buckle can be swapped. Buyers should confirm the reference, price and delivery with an authorised retailer, since the brand's own listing could not be checked for this report.
Background
The Master Ultra Thin is the slimmer sibling of Jaeger-LeCoultre's Master line, which Monochrome dates to the Master Control of 1992. Our histories cover the Jaeger-LeCoultre brand, the Master Ultra Thin, the Master Control and the Reverso. If you are weighing dress watches, see our comparison of the Cartier Tank and Jaeger-LeCoultre Reverso. For another small gold case this season, read our note on the Breitling Superocean Heritage 36 in yellow gold.Sources: Monochrome, Luxe Digital, Haute Time, Mr Watchmaster, Element in Time, The Hour Markers and The Manual, retrieved October 21, 2026. We could not read the brand's own product page, so specifications come from these outlets. Prices are indicative and may change by market.
Frequently Asked Questions
What is the Jaeger-LeCoultre Master Ultra Thin Moon 36mm pink gold reference number?
Q1242521, according to Haute Time, Mr Watchmaster, Element in Time and The Hour Markers.
How much does the Jaeger-LeCoultre Master Ultra Thin Moon 36mm cost?
US$23,100, EUR 23,900 or CHF 19,800, per Monochrome. Mr Watchmaster gives GBP 20,700. Prices are indicative.
What movement is in the Master Ultra Thin Moon 36mm?
The in-house, self-winding Calibre 925 with a 70-hour power reserve, running at 4Hz, with an open-worked 22k pink gold rotor.
How thick is the Master Ultra Thin Moon 36mm?
9.3mm, with a 36mm diameter and a 4.9mm-thick movement. One outlet gives 9.34mm.
Is the Master Ultra Thin Moon 36mm pink gold a limited edition?
No limit has been announced. Monochrome says it joins the permanent collection and is available immediately.
Is the Master Ultra Thin Moon 36mm water resistant?
It is rated to 50 metres (5 bar), which suits daily dress wear rather than swimming.
What is the difference between the 36mm and 39mm Master Ultra Thin Moon?
Both use Calibre 925. The 36mm is smaller, puts the moon and date sub-dial nearer the edge, and is about EUR 4,500 cheaper than the 39mm gold editions, per Monochrome.
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