Astron (wristwatch)
The Astron wristwatch, formally known as the Seiko Quartz-Astron 35SQ, was the world's first "quartz clock" wristwatch. It is now registered on the List of IEEE Milestones as a key advance in electrical engineering. History 
The Astron was unveiled in Tokyo on December 25, 1969, after ten years of research and development at Suwa Seikosha (currently named Seiko Epson), a manufacturing company of Seiko Group. Within one week 100 gold watches had been sold, at a retail price of 450,000 yen (US$1,250) each (at the time, equivalent to the price of a medium-sized car). Essential elements included a XY-type quartz oscillator of  (8192 = 213), a hybrid integrated circuit, and a phase locked ultra-small stepping motor to turn its hands. According to Seiko, Astron was accurate to ±5 seconds per month or one minute per year, and its battery life was 1 year or longer. Anniversaries 
In March 2010, at the Baselworld watch fair and trade show in Switzerland, Seiko previewed a limited edition new version of the watch and related designs of the original Astron watch, commemorating the fortieth anniversary in December 2009 of the debut of the Astron watch. Second Generation 
Seiko used the "Astron" trademark again as "Seiko Astron" when it released a satellite radio-wave solar-powered wristwatch using GPS satellites in 2012. 50th Anniversary Model 
In 2019, Seiko released several limited edition Astron models to commemorate the 50th anniversary of the quartz Astron. Among them, the model produced in a limited edition of 50 pieces (3.8 million yen) mimics the original case design and has a rough engraving pattern by craftsmen belonging to Epson's "Micro Artist Workshop". Footnotes
 
 
  (alternate version )

References

Further reading 
 "Seiko Quartz 35 SQ: The Seiko 35 SQ Astron was the first quartz watch on the market", Smithsonian Institution website. Thompson, Joe, "1969: Seiko’s Breakout Year", WatchTime Magazine, December 20, 2009

Products introduced in 1969
History of electronic engineering
Watch models
Seiko
Epson
Japanese inventions