Meet Jaeger-LeCoultre Master Ultra Thin (ref. 1682401), an elegant watch engineered for daily versatility and long-term reliability. From profile to crystal, the architecture convinces: crafted in pink gold and measuring 40 mm in diameter, with a thickness of 10.7 mm, defined by a round silhouette, paired with a gem-set bezel. The caseback is open, and the crystal is sapphire, delivering water resistance to 5000 meters. Up close, the dial rewards inspection: a ivory tone with matte finish, framed by gem-set indexes hour markers, and dauphine hands. Inside, precision takes center stage: the 978G caliber. Introduced in 2019. Designed for real-world wear, the watch transitions smoothly from tailored looks to casual settings. Manufacturing tolerances and surface treatment highlight consistent quality control. For buyers researching specifications and real-world impressions, this reference stands out for coherent design, dependable mechanics, and lasting relevance within modern horology.