Jaeger-leCoultre REVERSO TRIBUTE CHRONOGRAPH Manual page 30

The central seconds hand will turn, and
the minute counter will run. Pressing
the push-piece at 2 o'clock again will
stop the chronograph, enabling the time
measurement to be read.
- Reset by pressing the push-piece at 4
o'clock to be ready to perform another
time measurement.
- It is possible to add up several timing op-
erations by pressing on the push-piece at
2 o'clock again (without having to reset
the counter). Timing starts again and is
added to the previous measurement.
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