One of the rarest high-precision quartz watches
in the world is mine.
I was able to purchase a Sjöö Sandström UTC Ocean
Race Chronometer Extreme Black, number 18 (serial 3018) of
100 ever made.
It has the only digital only thermocompensated quartz movement
in the world (I describe it more in my earlier Sjöö Sandström thread
here on the forum).
When the watch is in “sleep mode” it is almost totally black, and when you
push a button it opens up and shows the time, day and date (perpetual calendar
programmed until the year 2099). If it is dark when you push the button, the
photocell located just beneath the display screen, senses that and automatically
activates the red backlighting.
The watch also has/shows: month, week, year, UTC, time in 25 different cities in the
world, chrono, downward counter for race starts, pin locked pin code memory for seven pin codes and alarm.
The watch is water resistant to 100m and has a screwed in back. It is delivered with a black calf skin strap.