101

The Jaeger-LeCoultre Calibre 101 is a hand-wound mechanical movement renowned as the smallest mechanical caliber in the world. First introduced in 1929 and still in production, it measures just 14.0 × 4.8 mm with a thickness of 3.4 mm, yet comprises 98 components and 19 jewels. Its compact size allows it to be seamlessly integrated into high jewellery creations without compromising aesthetics. Calibre 101 powers hour and minute functions and operates at a frequency of 21,600 vibrations per hour (3 Hz). It provides a power reserve of approximately 33 hours. Entirely designed, produced, and assembled in-house by Jaeger-LeCoultre, it remains a hallmark of miniature horological craftsmanship.