Photo of Caliber 9R16

Manual-winding Spring Drive

Caliber 9R16

Caliber 9R16 is a version of Caliber 9R66 specially adjusted to deliver an even higher level of precision. Caliber 9R66 delivers a precision rate of ±15 seconds per month (equivalent to ±1 second per day), whereas Caliber 9R16 delivers ±10 seconds per month (equivalent to ±0.5 second per day).
The difference between the two movements lies in the choice and testing of the quartz crystal oscillator. While all 9R Spring Drive movements use a quartz crystal oscillator in the regulator, only oscillators which exhibit particularly excellent performance are selected for use in Caliber 9R16.

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

"GMT" stands for Greenwich Mean Time, and uses a 24-hour hand (GMT hand) as the fourth hand on the watch dial in addition to the hour, minute and second hands.


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
-Dual time function with 24-hour hand
-Quick correction function of time difference adjusting to a calendar

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.