News · Jaeger-LeCoultre

Jaeger-LeCoultre hides Calibre 101 beneath 1,028 gemstones

The 101 Secrets is limited to three pieces and uses a hidden button to reveal its mother-of-pearl dial inside gem-set pink gold.

Hen & Mills Editorial · 3 min read · 10 September 2026

• Holding a hidden button at 6 o'clock makes a bracelet section pop open to reveal the mother-of-pearl dial.
• Each pink-gold piece carries 904 diamonds and 124 pink sapphires, with 163 hours of gem-setting.
• Reference Q2872310 is limited to three watches and its price is available upon request.

Jaeger-LeCoultre has turned its tiny hand-wound Calibre 101 into the concealed centre of a high-jewellery bracelet. The 101 Secrets, announced on 9 September 2026, hides its mother-of-pearl dial beneath a gem-set section operated by a button at 6 o'clock. Only three will be made. Each pink-gold watch is set with 904 diamonds and 124 pink sapphires, with the manufacture recording 163 hours of gem-setting for the finished piece.

The dial appears on command

The watch's name refers to both the movement and the concealed display. At rest, the bracelet presents a continuous field of stones. Holding down a hidden button at 6 o'clock causes one section to pop open like the pages of a book, exposing two hands for the hours and minutes. Releasing the button hides the dial again, restoring the bracelet's continuous gem-set surface.

Secret watches have historically allowed a time display to sit inside a jewel. This one makes the act of revealing the time part of its engineering. The button-operated section, dial and complete Calibre 101 fit into a watch head measuring 29.07mm by 12.22mm and 9.88mm thick, integrated into an articulated pink-gold bracelet sized for a 160mm wrist.

Calibre 101 measures 14mm by 4.8mm

The current Calibre 101 measures 14mm long, 4.8mm wide and 3.4mm thick. It contains 98 parts, runs at 21,600 vibrations per hour and provides a 33-hour power reserve. The movement is manually wound and its published functions are hours and minutes.

Jaeger-LeCoultre describes Calibre 101 as the world's smallest manually wound mechanical movement and the oldest calibre still in production at the manufacture. The company says it weighs less than one gram and requires 40 hours to assemble. Those figures give the 98-part count useful scale: the work is not only to make each component small, but to assemble the complete movement within the narrow format.

Jaeger-LeCoultre introduced the original Calibre 101 in 1929 and has continued to use the architecture for miniature jewellery watches. This 2026 execution keeps the movement's role precise. Its published dimensions are 14mm by 4.8mm by 3.4mm, allowing Jaeger-LeCoultre to integrate mechanical hours and minutes within the narrow gem-set bracelet. The movement serves the jewellery instead of dominating it.

Pink sapphires draw the outline

The bracelet and watch are made in 18-carat pink gold. Jaeger-LeCoultre specifies 124 pink sapphires totalling about 16.39 carats and 904 diamonds totalling about 13.26 carats. The larger coloured stones establish the bracelet's rhythm, while diamonds fill the links, watch cover and surrounding surfaces. The mother-of-pearl dial becomes visible only when the wearer chooses to open the mechanism.

The manufacture records 163 hours of gem-setting for each watch. That figure excludes movement assembly, case making and the work required to build the reveal mechanism. It is useful because it puts the decorative labour on the same footing as the technical specifications. With a total of 1,028 stones, the setting is not an applied border around a normal watch case; it is the material from which the bracelet's entire appearance is constructed.

Seven graduated shades of pink sapphire run from intense cyclamen to a pale blush. Jaeger-LeCoultre says the coloured stones use griffe setting to admit more light, while grain setting is used for the line of diamonds between them and around the dial. Grain-set sapphires and diamonds continue along the case sides. That continuity lets the hidden watch section sit inside the bracelet without interrupting the sequence of colour when the dial is closed.

Miniaturisation changes the priorities

Calibre 101 has a 33-hour power reserve. The movement is designed to disappear within the bracelet. The narrow 12.22mm watch-head width is the more telling number. It allows the watch to read as a bracelet from across a room, while remaining a manually wound mechanical watch.

The display is deliberately restrained. There is no seconds hand, date or power-reserve indicator in Jaeger-LeCoultre's published function list. The 101 Secrets uses complication in a different sense: not a stack of indications, but the coordination of miniature mechanics, a button-operated reveal and dense gem setting within a single piece of articulated jewellery.

The bracelet has to work as more than a setting surface. Its links must articulate around the wrist while keeping the stone layout coherent, and the concealed watch head cannot break that flow when closed. The specified 160mm wrist size is therefore not a casual strap measurement. It describes an integrated object whose fit, clasp, watch mechanism and gem pattern were designed together.

Jaeger-LeCoultre 101 Secrets price and availability

Reference Q2872310 is limited to three pieces. Jaeger-LeCoultre lists the price as available upon request, and the bracelet is specified for a 160mm wrist. The manufacture has not published broader availability or fitting details.