The JLC 846 is a watch movement from Jaeger-LeCoultre.
The 846 (and similar JLC 846/1) were introduced in 1975 and are still used in Lady- and Classique Reverso watches. It is an evolution of the earlier Reverso movements, specifically the 1960 JLC 490 and 1942 JLC 460.
Calibre 846 is a hand-winding movement made up of 93 pieces. It runs at 21600 vph, has 18 jewels, and a power reserve of 40 hours.
Jaeger-LeCoultre currently uses this calibre in 6 smaller Reverso models, ranging from the inexpensive Reverso Lady to the 500,000 Euro La Rose.