Mechanism: The Cal. 1161 began service in 1964 in the ref. 6544, a midsize, steel example of the range, and ended in the early seventies in the ref. 6807. Rolex replaced this with the Cal. 1570, which introduced a seconds hacking feature. Although often regarded as the entry-level Rolex, and the watch that represents the buy in to the brand for new collectors, the Oyster Perpetual range still benefits from the same level of engineering excellence and attention to detail as anything else that bears the Rolex name, and nowhere more so than in its mechanism.

In addition, the Rolex 1161 is a chronometer certified movement, rated accurate to within -4/+6 seconds a day. Also, its free-sprung Nivarox hairspring features a Breguet overcoil, and it has a power reserve of 42 hours. Its balance wheel is regulated by Rolex’s Microstella system, two pairs of weighted screws on the inside of the balance rim that makes the wheel more aerodynamic and its adjustment easier to fine tune.

Family Notes: In 1926, Hans Wilsdorf introduced the Oyster watch which used a waterproof case, hence the name. He added "Perpetual" to the name when in 1933 he introduced a reliable automatic self-winding watch. Hence the name means "Waterproof, Self-Winding" in Rolex-speak and generally means the watch is water resistant to a depth of 100 meters.