Hacking (Second Stop)
Hacking is the feature whereby the seconds hand stops the moment you pull the crown out, letting you set the watch to another timepiece right down to the second. Not every mechanical movement offers it.
On a watch with hacking, pulling the crown to its outermost position stops the seconds hand; push it home on the right second and the watch starts in perfect sync. This matters to anyone who likes to set the time to more than just the minute. The feature is not a given at this price: Seiko's newer 4R36 and Orient's F6922 both hack, whereas the older Seiko 7S26 does not. When buying a mechanical watch, it is worth asking whether the movement hacks.