Calibre 910 and Calibre 911 were manual winding alarm movements from Jaeger-LeCoultre.

Introduced in 1962, Calibres 910 and 911 replaced Calibres 814 in the Jaeger-LeCoultre Memovox range. These were produced in large numbers, with 75,000 movements made through 1979.

As in previous Jaeger-LeCoultre calibres, Kif shock protection was added, giving the name, Calibre K910 and Calibre K911. At some point, all of the calibres got Kif protection and the “K” was dropped.

As in other Jaeger-LeCoultre alarm calibres, the alarm hammer struck a protuberance on the back plate, making a distinctive buzzing sound. Even if the alarm was not wound, the hammer rattled freely against the protuberance.

• 13 lignes in diameter, 5.15 mm thick (910) or 5.6 mm thick (911)
• Glucydur balance, automatically compensating flat hairspring
• 19,800 A/h
• Double barrel (time and alarm)
  • Unidirectional bumper automatic winding for time
  • Manual winding for alarm
• Direct sweep central seconds
• 17 jewels
• Alarm hammer inside case back

Jaeger-LeCoultre Alarm Calibres

• A Little Potted History Of The Memovox & My Recently Acquired Cal 911
• Three Cheers for Memovox!