This 5719-8990 Seiko Chronograph watch was issued to pilots of the Japan Air Self-Defense Force, the equivalent of the Japanese Air Force, in the late 1960s.
The case back is engraved with the words "Air Self-Defense Force", logo and control number.
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Speed timer versions of the 1970s Air Self-Defense Force model are occasionally found, but other examples of this monopusher chronograph version from the 1960s are hard to find.
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The case and movement have been fully overhauled and replaced with rare NOS pusher buttons and NOS glass.
The bracelet was newly fitted with a genuine NOS monopusher chronograph bracelet.

Government-issued items of the Self-Defense Forces are strictly controlled, so only those released from retired former Self-Defense Force officers can be found on the market.
This 5719-8990 version is the one and only military watch.

Brand： Seiko
Model： Monopusher chronograph
Moement： Cal.5719A
Face Color： Black Dial
Case material： Stainless Steel
Bracelet ： NOS Genuine
Service： Fully overhauled
accuracy of time∶ about ±30s/day ※Some errors may occur depending on usage conditions, etc.
Measured by a Timegrapher
± 10s / day at Dial up position
* There are some errors in the actual accuracy.

After winding the mainspring, shake it slightly from side to side.
【When winding the mainspring, do not use force and wind it slowly. If you cut the mainspring, it is not covered by the warranty.】