Some specifications for this reference are on file; the record is incomplete.
Seiko · Astron
Astron
Ref. 35SQ Astron — “The first quartz wristwatch”
discontinuedFirst production quartz wristwatchPartially documentedLast reviewed Not yet reviewed
Missing informationCore fields not yet documented for this reference: Water resistance
Authentication Notes
Combination
HighProbable
Assess against the manufacturer's archive, not the market
Very few examples exist and the historical stakes are high. Specification comparison against other listings is close to worthless here, because the population of listings is small enough to be dominated by any single misdescribed watch. Direct enquiry to Seiko's corporate archive or museum is the appropriate route, and its absence should be stated as a limitation of any assessment.
Inspection points
No inspection checklist has been published for this reference.