Introduction and Launch: The Rolex calibre 3131, an automatic movement found in models like the Milgauss and Air-King, represents an upgrade from the calibre 3130. Notably, it introduced the Parachrom hairspring in 2001, enhancing resistance to shocks and magnetic fields for improved accuracy and durability. Introduced at Baselworld 2007, the calibre 3131 is a time-only, three-hand automatic movement without a date function. Initially featured in the anti-magnetic Milgauss, it also powers the 2016 Air-King 40, showcasing Rolex's commitment to robust, precision-engineered movements.
