Grand Seiko caliber 9S86
Self-winding 'high-beat' movement with GMT functionality. This high-specification movement delivers the same accuracy (-5 to +3 seconds a day) and the same power reserve (55 hours) as the core Caliber 9S85, while also offering the GMT function that the international traveler needs to ensure that the accuracy of the time shown is not compromised when the time zone is changed. The GMT hand shows the time in the home time zone. Pulling the crown out by one notch enables the hour hand to be adjusted without stopping the second hand so that the highly accurate timekeeping delivered by the Hi-Beat 36000 is not lost.
The redesigned hairspring and mainspring complement cutting-edge MEMS technology to raise precision and reduce component weight, simultaneously improving durability and securing the torque necessary to maintain a rate of 36,000 oscillations per hour. The movement is practical and reliable, with a maximum power reserve of about 55 hours.