As well as offering the legendary reliability and minimalist look of the Master line, Ultra Thin watches add a new feat: an extremely sophisticated technical achievement. In its 39 mm diameter case, the Master Ultra Thin Réserve de Marche expresses a watchmaking philosophy that strives to reduce functions and their representations to the bare essentials.
The Jaeger-LeCoultre 938 automatic calibre has all the attributes of a precise mechanism with its 43 hour power reserve. Endowed with the robustness of Jaeger-LeCoultre movements, it adapts to its designers' wish of keeping it as thin as possible. The objective has been achieved with a calibre that does not exceed 4.9 millimetres and can be inserted into a case that is so slim that it imposes a general minimalism with a total height of just 9.85 millimetres.
In its constant quest for perfection, two decades ago the Manufacture established a rigorous control procedure to test the tiniest details of its watches' quality and robustness in the most improbable circumstances: the 1,000 hours test. None of the watches in the Master Control collection may leave the Manufacture workshops without a certificate stating that they have brilliantly passed the tests of this gruelling 6-week programme. The Master Ultra Thin Réserve de Marche has passed all the 1,000 hour tests with flying colours.
Connoisseurs who like to wear a work of art of exemplary precision on their wrists have made the Master Ultra Thin Réserve de March a best-seller in the Master Control line. In 2012, this design, dedicated to slimness, continues its quest for the bare essentials: its profile is sharper and the dial is even more legible with a new case diameter. But the heart of the watch remains intact and perfectly preserved with a display system that guarantees instant reading of clear, obvious functions, useful for everyday purposes.
What more can one ask of a watch that is ready to provide the most precious of services for decades? Perhaps there is a fleeting moment of doubt as the lover of fine watches hesitates between the silver-plated sundial steel model and the pink gold version with its dial in a delicate eggshell shade.