To make it short, this was the most accurate Seiko watches they made in the '70s. And also, possibly one of the most accurate civilian watches among all brands in the world. Yet, it still ranks among the tops nowadays in terms of accuracy, after 40 years it had reached the market. Now you see how superior it is.
Different from some other watches offered at that time, Seiko stepped ahead of the others by using two high end quartz in the movement. One responsible for the time keeping part of the movement, the other is used for regulating the fine adjustment to the time keeping logic, by detecting the temperature where it affect the accuracy. This method results a huge improvement to the general accuracy to the movement. Where most other watches still use seconds-per-month to rate theirs, the twin quartz equipped models by Seiko, used seconds-per-year to show its superb accuracy. And this SUPERIOR, is the best among all of them, featuring an accuracy of 5-seconds-per-year!
The cost of this watch was expensive, very expensive. Some had said that it cost about the same as getting a Japanese car back in those days, at 230,000 yen a piece! You can see the prices in the photos below. Even nowadays, a good example of this watch still sell at premium, targeting mostly to collectors, as this is one important model that marks the history, and still maintain good performance, with very little servicing. This is an amazing watch indeed.
Eric has been a gadget lover for decades and had been collecting affordable vintage since the nineties. With his passion for vintage watches, he had been sharing thoughts and photos in interest groups, with his intention of raising public interests on forgotten classics.