One tick for every second. It’s a dead giveaway that the watch you’re seeing has a quartz movement. And if you see a Rolex ticking like this, it likely means that the watch is either 1) the little-seen Rolex OysterQuartz or 2) a shameless fake with a quartz movement.
But there’s a very improbable third option: the watch you’re seeing is a Rolex Tru-Beat, a bizarre little piece of timekeeping obscura with an incredibly rare complication: a deadbeat seconds hand.
What’s a deadbeat, again?
The deadbeat is one of watchmaking’s greatest ironies. It ticks once a second, precisely like your garden variety quartz, but it’s mechanical.
In fact, it requires a remarkably complex mechanism inside to make that mechanical movement, which would usually advance the seconds hand several times a second, to move just once a second.
The complication was initially invented way back in 1675 when it was put into a regulator clock but the function didn’t show up in the wristwatch until the 1950s. This is where the Tru-Beat comes in.