The reliability and precision of an ordinary mechanical watch can be affected by a magnetic field of 50 to 100 gauss. But many scientists are exposed to much higher magnetic fields during the course of their work. Rolex’s solution was the Milgauss, created in 1956, the first watch of its kind. Hence the name of the watch, mille being French for thousand.
The reference 116400 was introduced in 2007. The black dial model (non-GV) was discontinued in 2013. The Z-Blue version was added in 2014.
Movement
Calibre 3131 is a self-winding mechanical movement entirely developed and manufactured by Rolex. Like all Rolex Perpetual movements, the 3131 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.
