Known across Switzerland as “The Watchmaker’s Watchmaker” for supplying historic movements to Patek Philippe, Audemars Piguet, and Vacheron Constantin, Jaeger-LeCoultre (JLC) crafts perhaps the purest 39mm dress watch on Earth: the Master Ultra Thin Moon (Ref. Q1368430 / 1368420 / Q1362520). In 2026, APS Factory (APSF) and GF / YLF produce a true-clone Calibre 925/1 edition measuring just 9.3mm thin with a synchronized 6 o’clock moonphase and pointer date.
- True Clone JLC Calibre 925 (70-Hour Upgraded Barrel): APSF cloned the 253-part JLC Calibre 925/1 from scratch—featuring blued steel movement screws, openworked pink-gold-toned JL rotor, and exact 9.3mm case slimness.
- Dual-Polished Dauphine Hands: Each Dauphine hour and minute hand is split down its central ridge with one half satin-brushed and the other half mirror-polished to maximize legibility at any angle.
- 3D Starfield Moonphase Disc & Pointer Date at 6 o’Clock: Both the lunar phase disc and the outer 1–31 pointer ring advance automatically at midnight (and adjust via flush case-side correctors).
- JLC Polaris Geographic & Mariner: Sporty internal-bezel compressor divers with dual crowns and world-time complications.
1. Master Ultra Thin Moon 39mm: Silver, Black, Midnight Blue & Rose Gold
Slide our Jaeger-LeCoultre Master Ultra Thin Moon 39mm Steel, JLC Master Ultra Thin Moon Black/Blue Sunburst, or the warm 18k-wrapped Jaeger-LeCoultre Master Ultra Thin Moon Pink Gold under a tuxedo cuff. Unlike bulky modified Miyota dress watches, APSF’s dedicated Calibre 925 places the balance wheel at the exact 7 o’clock caseback position with a smooth 28,800 vph sweep and whisper-quiet ceramic ball-bearing rotor.
| JLC Master Ultra Thin Spec | Genuine JLC Q1368430 | APS Factory (APSF Cal.925) | Older Miyota 9015 Clones |
|---|---|---|---|
| Case Dimensions | 39.0 mm × 9.30 mm | 39.0 mm × 9.30 mm (Exact) | 39.0 mm × 10.1 mm |
| Movement Architecture | JLC Calibre 925 (28,800 vph) | True Clone Cal.925 (No Deco Plate) | Noisy Miyota + Overlay Plate |
| Moonphase & Date | True 29.5-Day Lunar Cycle | True Lunar Cycle (Once/Month) | 24h Sun/Moon Indicator |
| Dauphine Hand Finish | Half-Satin / Half-Mirror | Exact Dual-Finish Ridge | Flat Polished Hands |
| Deployant Buckle | Double-Fold JLC Clasp | Engraved JLC Folding Clasp | Generic Tang Buckle |
2. JLC Polaris Geographic & Reverso Duoface Classics
For collectors who want a sportier 42mm dual-time travel watch from Le Sentier, explore our Jaeger-LeCoultre Polaris Geographic 904847J Steel, or browse the iconic Art Deco swiveling case in our Jaeger-LeCoultre Reverso Collection.
- ⌚ JLC Master Ultra Thin Moon 39mm Silver Sunburst — APSF True Clone Calibre 925 & 9.3mm Profile
- ⌚ JLC Master Ultra Thin Moon 39mm 18k Pink Gold — Eggshell Opaline Dial & Gold Moonphase Disc
- ⌚ JLC Master Ultra Thin Moon 39mm Classic Edition — Dual-Finished Dauphine Hands & Exhibition Back
- ⌚ JLC Polaris Geographic 42mm World-Time — Dual Crowns & 24-City Timezone Ring
Collector FAQ & Pre-Shipment QC Answers
Does the moonphase on the APSF JLC Master Ultra Thin Moon turn once a day or once a month?
It is a true lunar moonphase that advances one click at midnight over a 29.5-day lunar cycle (not a cheap 24-hour day/night disc!).
When is it safe to use the recessed moonphase and date pusher pins?
Always set the main watch hands to 6:00 first before pressing the case-side corrector pushers so the midnight calendar driving finger is completely disengaged.
