Rolex caliber 3136
Calibre 3136 is a self-winding mechanical movement entirely developed and manufactured by Rolex. Like all Rolex Perpetual movements, the 3136 is a certified Swiss chronometer, a designation reserved for high-precision watches that have successfully passed the Swiss Official Chronometer Testing Institute (COSC) tests. The 3136 features a Parachrom hairspring and high performance Paraflex shock absorbers developed by Rolex, offering greater resistance to shocks and to extreme conditions. Its architecture, in common with all Oyster watch movements, makes it singularly reliable.