The JLC 101 (also called “Calibre 2 ligne”) is an extremely compact watch movement from Jaeger-LeCoultre.
Introduced in 1929, the JLC 101 is still in use today and retains its title as the world's smallest mechanical watch movement. It is legendary for its compact dimensions Just 14 mm long, 4.8 mm wide, and 3.4 mm high, and weighs just 1 gram. Jaeger-LeCoultre is limited to making just 50 Calibre 101 movements each year due to the custom parts and special skills required.
The JLC 101 is produced in two versions
It is a hand-wound movement made up of 98 pieces designed for extremely compact applications. It runs at 21600 vph, has 19 jewels, and a power reserve of 33 hours.
Jaeger-LeCoultre currently uses this calibre in 3 watches.