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.
| Movement | Winding |
| Mechanical | Bidirectional, automatic |
| Functions | Calibre |
| Centre hour, minute and seconds hands. Stop-seconds for precise time setting | 3131 Calibre, Manufactured by Rolex |
| Water-Resistance | Oyster Architecture |
| Waterproof to 100 metres / 330 feet | Monobloc middle case, screw-down case back and winding crown |