Seiko SQ

Seiko "SQ" or "Seiko Quartz" was simply an abbreviation put in a range of watches meant for many vintage (quartz) watches that were not JDM, but export market models.

The SQ is therefor a bit of a weird range, as it goes from entry-entry quartz 3-hand watches to later the 7A28 SQ150 Sports which was the revolutionary chronograph movement, perhaps the best quartz caliber Seiko ever produced ;-)