Ultra Thin

Jaeger-LeCoultre’s Ultra Thin watches share a preference for slender cases and restrained dials, but not a single movement or layout. The family stretches from spare, hand-wound two-hand watches to automatic models with dates, moon phases, and power-reserve displays—quite different propositions beneath a similar dress-watch silhouette.

The hand-wound Master Ultra Thin models built around caliber 849 offer the clearest expression of that restraint: hours and minutes, with no seconds hand disturbing the dial. The movement itself measures just 1.85mm thick. Later automatic branches bring more everyday information: the Master Ultra Thin Date, associated with caliber 899, keeps its calendar in a window, while the Master Ultra Thin Moon pairs a moon-phase display with a pointer date at six o’clock, using the caliber 925 family.

The Master Ultra Thin Réserve de Marche takes another route, balancing separate displays for power reserve, date, and running seconds. Across generations, case dimensions, dial proportions, and movement specifications have changed; even familiar variant names can conceal revisions. A two-hand dial, calendar window, or cluster of subsidiary displays tells you which branch you’re looking at, rather than necessarily which generation.