The original replacements to the Grand Seiko were the Seiko Grand Quartz, and they made them even more accurate by fitting two quartz crystals.


From the serial number on the case back we can accurately date this watch to being made in March 1978.  This is very early in their production.


The Grand Seiko models were first made to provide high quality, very accurate timepieces to compete with the very best the Swiss could offer.  In the end they were phased out due to internal competition though – nothing they could make would be as accurate as a quartz watch (Seiko were the brand who pioneered quartz watches, back in 1969).  By 1975, Seiko launched the Grand Quartz model range, and by 1978 they introduced the Twin Quartz movement 9943.  This increased accuracy from +/- 10 seconds a month, to +/- 10 seconds a year, and the way to tell the difference is the logo at 6 shows two quartz crystals, and can not be mistaken for the anything else (unlike the single crystal logo, while the childish might think looks like a cock and balls!)

This example has pluses and minuses.  The dial has patina all around the edge, but most noticeable between 4 and 8.  The bracelet isn’t original, or even made by Seiko, but it does suit the watch.  The crown also has the double quartz logo, so is original, and everything including the quick set day date is working well.  The watch is keeping time well, but we have no way of measuring that to the tolerances that were originally specified – when a chronometer rated watch has to be +6/-4 seconds a day, +/- 10 seconds a year is beyond ways we can measure!

This watch will be supplied with our Certificate of Authenticity.

Please see the HD video for more detail.  All photos and videos are part of the description and are of the actual watch unless mentioned.  We do not photoshop any pictures, and the images are copyright of and should not be used without permission.


Width with crown  36.6 mm

Width without crown  35.4 mm

Between lugs  19 mm

Lug to lug length  41.1 mm

Case Thickness  8.7 mm

Bracelet will fit a maximum wrist size of 195 mm

All sizes are approximate.

Included with this watch is a 3 month guarantee and free delivery to UK addresses.  If you live outside the UK we can still deliver to most countries.  Please see our Worldwide Shipping information, or Contact Us.   Payment can be made by most credit or debit cards, bank transfer or PayPal.