JAEGER-LECOULTRE MASTER ULTRA THIN DATE

The story behind this Jaeger-LeCoultre Master Ultra Thin Date

The Jaeger-LeCoultre Master Ultra Thin Date continues a tradition of the Manufacture du Sentier, in the Vallée de Joux: that of ultra-thin movements. As early as 1907, the Maison had already unveiled the calibre 145, a pocket watch movement just 1.38 mm thick. The Master range has inherited another standard: the 1,000-hour test introduced in 1992, a series of tests carried out on the movement and then on the assembled watch. The Q1238421 model features the collection’s signature design with reworked hour markers – longer and slimmer – and a date window now positioned at 6 o’clock, aligned with the logo and the 12 o’clock hour marker. The dial features only the essentials: the brand’s signature, the word ‘Automatic’ and the inscription ‘Swiss Made’.

Case, calibre and strap of this Master Ultra Thin Date

The polished steel case measures 39 mm in diameter and 7.89 mm in thickness, with a slim bezel, curved lugs and a crown stamped with the JL monogram. The silver-grey sunburst dial features faceted applied hour markers, dauphine hands and a dot-marked minute track around its periphery. The calibre 899 is a 3.3 mm-thick in-house automatic movement, comprising 218 components and 32 jewels. It beats at 28,800 vibrations per hour and offers a 70-hour power reserve. The sapphire crystal case back reveals the oscillating weight, open-worked with the Maison’s monogram, and bears the 1,000-hour test mark. It is water-resistant to 5 bar. The watch is fitted with a black alligator strap with large scales, secured by a steel folding clasp bearing the Jaeger-LeCoultre signature.

Why this Jaeger-LeCoultre watch

A 39 mm dress watch with a date display remains the most versatile configuration in a classic collection. At 7.89 mm thick, the watch slips easily under a shirt cuff, and the 70-hour power reserve keeps the Calibre 899 running from Friday evening to Monday morning without needing to be wound. The silver-grey dial remains easy to read, with no numerals or superfluous decoration, and the date at 6 o’clock balances the overall design. As a pre-owned piece, this latest-generation Master Ultra Thin Date comes with its original documentation and a manufacturer’s warranty that is still valid, allowing you to purchase it whilst retaining the brand’s after-sales support.

Contents and condition

This watch is supplied as a full set, with its Jaeger-LeCoultre wooden presentation box, outer box, booklet and international warranty card dated February 2026. It has been worn and shows only slight signs of external wear. The case, dial and strap are in excellent overall condition, and the buyer will receive a recent watch, ready to wear upon receipt.

Warranty and delivery

The Swiss Collector guarantees the authenticity of this watch, which remains covered by the Jaeger-LeCoultre manufacturer’s warranty. We accept returns within 10 days in accordance with our terms and conditions. As Switzerland’s leading second-hand retailer, backed by the largest network of boutiques, we offer online booking for a fitting and in-store collection, or fully secure international delivery.