Small Size Automatic

Caliber 9S27

The Grand Seiko automatic caliber 9S27 strikes that difficult and delicate balance between high performance and slimness. The latest Spron alloy is used for the balance spring and both the pallet fork and escapement wheel are made by MEMS engineering.


Winding mechanism Automatic with manual winding mechanism
Mean daily rate*1 +8 to -3 seconds per day
Normal usage accuracy +10 to -5 seconds per day
Power reserve Approximately 50 hours
Vibrations 28,800 vibrations per hour (8 beats per second)
Number of jewels 35 jewels
Features -Date display
  1. Mean daily rate is a mean value of daily rates in a condition where the movement before assembly in a case is measured in six positions in a fixed manner under artificially controlled environment for 12 days.