The red sweeping seconds hand of this extremely rare mechanical Rolex jumps forward at every second, predating the behaviour of quartz watches by some 14 years. Jumping dead-seconds have only rarely been used throughout the history of horology, with only a handful being made as wrist watches. The red seconds hand draws the eye to what was, in the 1950s, most unusual behaviour, but unfortunately, most of the very few Tru-Beat watches ever made have had their jumping seconds devices removed, making intact examples like this exceptionally important.