Calibre 3180 is a self-winding mechanical movement entirely developed and manufactured by Rolex. It features a Parachrom hairspring and Paraflex shock absorbers, offering greater resistance to shocks and to extreme conditions. Like all Rolex Perpetual movements, the 3180 is a certified Swiss chronometer, a designation reserved for high-precision watches that have successfully passed the Swiss Official Chronometer Testing Institute (COSC) tests. Its architecture, in common with all Oyster watch movements, makes it singularly reliable. Caliber 3180 indicates the time in two time zones simultaneously and feature an elegant sun and moon day/night indicator in an aperture on the sub-dial for the second time zone.