Automatic spring Drive 3-Day

Caliber 9R15

Caliber 9R15 is specially adjusted Caliber 9R65, to deliver an even higher level of precision.
Caliber 9R65 is ±15 seconds a month (equivalent to ±1 second per day), whereas Caliber 9R15 is ±10 seconds a month (equivalent to ±0.5 seconds per day).
The difference between the two movements lies in the quartz crystal oscillator, which delivers accurate electrical signals.
All 9R Spring Drive use quartz crystal oscillator with stable accuracy. Among them, only quartz crystal oscillator, which exhibit particularly excellent performance, are selected and mounted on the Caliber 9R15.

The Grand Seiko lion in 18K gold graces the oscillating weight to symbolize the enhanced accuracy.


Winding mechanism Automatic with manual winding
Accuracy ±0.5 second per day (±10 seconds per month)
Power reserve Approximately 72 hours
Number of jewels 30 jewels
Features -Power reserve indicator

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.