Jaeger-LeCoultre Gives the Master Ultra Thin Moon a 36 mm Pink Gold Case

Jaeger-LeCoultre has brought a more compact dimension to one of its most recognisable modern dress watches.

The new Master Ultra Thin Moon Ref. Q1242521 places the familiar moon-phase and date display inside a 36 mm case in 18-carat pink gold, giving the watch a distinctly classical stance without moving away from contemporary automatic watchmaking.

For anyone who has been waiting for a smaller precious-metal dress watch with a traditional complication, this is a measured and elegant addition to the Master Ultra Thin line.

At a glance

• Jaeger-LeCoultre has introduced the Master Ultra Thin Moon Ref. Q1242521 in a 36 mm 18-carat pink gold case.
• The watch pairs a silver sunray-brushed dial with a combined moon-phase and date display at 6 o’clock.
• It is powered by the in-house automatic Calibre 925 with a 70-hour power reserve and is priced at €24,300 including VAT or US$23,200 before sales tax.

A smaller case with mid-century balance

The most important change here is proportion.

At 36 mm in diameter and 9.3 mm thick, the pink gold Master Ultra Thin Moon leans into the scale of classic round watches from the 1950s rather than the larger dress-watch dimensions that have shaped much of the modern market.

The polished 18-carat pink gold case keeps the design formal and restrained, with a rounded profile, curved lugs and a polished bezel that reinforce the watch’s dress character.

It’s a size that should speak to collectors who prefer vintage-influenced proportions, as well as anyone who finds the elegance of a thin round watch more persuasive than wrist presence for its own sake.

The moon-phase dial remains the centre of gravity

The dial keeps the essential Master Ultra Thin Moon formula intact.

A silver-coloured sunray-brushed surface gives the watch a bright, finely textured base, while the warmth of the case is picked up in the gilt hour markers and faceted Dauphine hands.

Those hands are not simply polished pieces of metal.

Each one combines a satin-brushed facet with a polished facet, creating a shifting contrast as the watch catches the light.

The combined date and moon-phase display sits at 6 o’clock, balancing the dial without crowding it.

The moon is set against a deep blue starry background, while the date track is printed in black around the aperture, keeping the information legible and visually contained.

Calibre 925 and the Manufacture approach

The Master Ultra Thin collection is closely tied to Jaeger-LeCoultre’s long experience with slim mechanical watches, a field the Maison has explored since the early 20th century.

Inside this model is Calibre 925, a self-winding movement developed and produced in-house at the Manufacture-Atelier in the Vallée de Joux.

The movement runs at 4 Hz and offers a 70-hour power reserve in its latest version, giving the watch nearly three days of running time when fully wound.

That longer reserve adds a practical benefit to an otherwise traditional dress watch, especially for those who rotate watches across a week.

The movement is visible through a transparent sapphire crystal case back.

Its finishing includes Côtes de Genève, bevelled bridges and blued screws, with an open-worked winding rotor in 22-carat pink gold adding another warm-toned detail to the view from the back.

Details & Specifications

The new 36 mm Master Ultra Thin Moon is not a reinvention of the line, and that’s precisely the point.

By reducing the case size and rendering it in pink gold, Jaeger-LeCoultre has sharpened the watch’s connection to classical dress-watch design while preserving the practical movement updates and refined finishing expected from the collection today.