Vacheron Constantin 1121

Caliber 1121 is an ultra-thin automatic movement from Vacheron Constantin, introduced in 1967 and still in production. It is based on the Jaeger-LeCoultre 921, which itself derives from the JLC 920, and adds a date complication to the base ultra-thin platform. The movement is not manufactured in-house by Vacheron Constantin, relying on the Jaeger-LeCoultre ebauche. It serves as the foundation for date-display versions within the brand's 11xx caliber family.