/fa/ - Fashion

>>15340541
The 9F is mechanically more interesting.
The seconds hand jumps twice in a single tick, so fast it's imperceptible to the naked eye.
The hand pivots are all individually sleeved (see pic).
There's a hairspring just to keep the seconds hand absolutely stable.
The geartrain is in a separate sealed compartment so even if you change the battery, there's no risk of dust etc. getting into the vital parts. This means many decades of worry-free use.
etc.