The JLC 410 (and similar) are the original movements for the Jaeger-LeCoultre Reverso watch.
Introduced in 1933, the 410 and 411 calibres were specially designed to fit in the Jaeger-LeCoultre Reverso watch. A 17 jewel movement, the 410 was extremely compact and tonneau shaped for the rectangular Reverso. Prior to this introduction, Jaeger-LeCoultre fitted the Reverso with Tavannes movements.
All movements in this family share the same basic design and dimensions. They measure 8 by 11 lignes (17.85 mm by 24.55 mm), and are 3.35 mm thick. They have 17 jewels and operate at 18,000 A/h.
The main difference between these movements are as follows