Looking at the shining bezel, hour markers, domed front dial and crystal, brushed case sidelines, 816.423 leaves an impression that has some kinds of connection to M177S. The overall workmanship of 816.423 is superb.
Based on the prototype of ST21, additional features like
the moon phase at 2 o’clock, power reserve indicator at 10 o’clock, date
sub-dial at 6 o’clock. make this watch appear more multi-functional and complicated,
while maintaining its advantage of 28800 high vibration per hour.
Crown at position 1 can be hand-wound by turning clock-wise to add power
- Pull out crown to position 2, second hand stops, turn crown to adjust time.
- Push upper right recessed button to quick-set moon phase
- Push lower right recessed button to quick-set date