The JLC 854/1 is a mechanical watch movement from Jaeger-LeCoultre.
The 854 was introduced in 1994 with the original Reverso Duoface. It originally included a small inset corrector to advance the GMT function, and watches came with a “stylus”. The 854/1 was introduced with the “updated version” Reverso Duoface and includes a large square button rather than the small pusher.
The calibre 854/1 contains 180 parts, including 21 jewels, and has a frequency of 21,600 vph (3Hz). It measures just 3.80 mm in depth.
Jaeger-LeCoultre currently uses this calibre in four Reverso Duoface models