1930s Jaeger LeCoultre Rare FB-Case 1st-Waterproof Black Sector dial

Jaeger LeCoultre, 1st waterproof model, rare FB case, Cal. 31 powered, black sector dial, circa 1930s. This is a very rare early waterproof model with a screw back waterproof case made by FB, which is rarely seen among Jaeger-LeCoultre watches. There is also a sub-seconds model with Cal.428, but this model is a two-hand model with Cal.31. The dial has a wonderful sector design unique to this era, and the rare black dial further improves the rarity fo this model. It is equipped with Cal.31, which was used for ladies' watch models in the same era, and the symmetrical design of the two-hand model highlights the beauty of the sector dial.