BY ( Cal. F7F4 )

About the Product

Features

This product is a mechanical self-winding watch (with manual winding).

  • Winding the mainspring provides the driving force to move the watch.
  • Vibration-resistant bearings are used to protect the balance from impact.
  • The power reserve indicator shows the remaining continuous operating time of the watch.
  • A second hand halt mechanism is provided.

Names and Functions of Individual Component Parts

A Hour hand
B Minute hand
C Small second hand
D Power reserve indicator hand
E Crown *1
0 0 click: Normal position (manual winding)
1 1st click: Time setting (second hand halt mechanism)
  1. Some models have a screw-down crown.
    >"How to Use the Screw-Down Crown"

  • The design of the dial and position of the crown may differ depending on the model.

Specifications

Oscillations 21,600 oscillations/hour
Daily rate +15 s to -5 s (static accuracy) *2
Drive method Mechanical (self-winding, manual winding)
Clock display Time (hour, minute, and second)
Number of jewels 24
Continuous operating time 50 hours min.
Manual winding (fully wound)
Number of crown rotations
Approx. 30
Self-winding
Direction of rotation
Both directions
Magnetic resistance Type 1 *3
Water resistance *4
  1. The daily rate is the amount the watch is fast or slow after 24 hours elapse.
    The static accuracy above is based on factory adjustment and warranty when under static conditions and at room temperature.
    Due to the characteristics of mechanical watches, the above static accuracy may go out of range due to the conditions of use (watch orientation, amount of mainspring winding, temperature, etc.).
    Do not evaluate the error over one day only, but over about one week.

  2. Watches with Type 1 magnetic resistance are reinforced to withstand magnetism.
    See the following for details about the magnetic resistance.
    >"Maintenance Guide > Effect of Magnetism" (opens new window)

  3. The water resistance performance is indicated on the case back.
    A watch with WATER RESISTANT indicated on it has enhanced water resistance performance.
    >"For Safe Use > Precautions Regarding Water Resistance" (opens new window)

  • Product specifications are subject to change without notice for improvement.