Automatic Spring Drive 3-Day Chronograph GMT

Caliber 9R86

Spring Drive Caliber 9R86 may well be the world's most accurate spring-driven chronograph. It delivers a precision of ±15 seconds a month, or ±1 second a day and, equally importantly, measures elapsed time not to the nearest fraction of a second but exactly, thanks to the fact that the glide motion hands stop at the very instant that the button is pressed.
The 72 hour power reserve is maintained even if the chronograph is in operation.

Specifications

Winding mechanism Automatic with manual winding
Accuracy ±1 second per day (±15 seconds per month)
Power reserve Approximately 72 hours
Number of jewels 50 jewels
Features -Power reserve indicator
-Dual time function with 24-hour hand
-Quick correction function of time difference adjusting to a calendar
-Stopwatch function

What makes 9R Spring Drive special?

Spring Drive, one of the great innovations in modern watch making history, regulates a spring-driven movement with state-of-the-art electronic technology that functions without batteries or other external power source. Its sole power source is a mainspring, which drives a series of gears. A rotor, connected to the end of these gears, generates a small electrical charge that activates an electronic circuit and quartz oscillator. Its accuracy is unprecedented for a watch wound by a mainspring. The development of the 9R Spring Drive movement was possible only because Grand Seiko is one of the few manufacturers with expertise in both mechanical and electronic watches.

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