Master Control Geographic Stainless Steel / Silver / Calf

In Context

At 40 mm it is sized to the current mainstream: 40 mm is the median across every watch measured in this catalogue. At 10.96 mm thick it is about average for a modern wristwatch. The case back is open, so the movement is visible without taking the watch apart, and the sapphire crystal will resist everything short of deliberate abuse. 50 m covers rain and hand-washing comfortably; it is not a watch to swim in.

The movement winds itself from the motion of your wrist. 70 hours of reserve is enough to set it down on Friday evening and find it still running on Monday. At 28,800 vph the seconds hand advances 8 times a second.

4128420 stands on its own in this catalogue — no other reference here shares its base number. It pairs a silver sunburst dial with a stainless steel case. Introduced in 2020.

Mechanical automatic winding movement, 295 parts, 28,800 vibrations per hour, 70-hour power-reserve. Functions: main time zone: hour, minute, central seconds, date, power-reserve, day/night indication. Second time zone: hour, minute, 24-city disc specifying summer time, 24-hour indication.

3 other watches in the library run the Jaeger-LeCoultre 939AA.

Jaeger-LeCoultre

Master Control Geographic Stainless Steel / Silver

Q4128421 · 40 mm

Jaeger-LeCoultre

Master Control Geographic Pink Gold / Silver / Alligator

Q4122520 · 40 mm

Jaeger-LeCoultre

Polaris Geographic Stainless Steel / Grey

Q9078640 · 42 mm