Originally developed in the 1950s in response from physicists, engineers and technicians exposed to major magnetic fields on a daily basis, the Rolex Milgauss is resistant to to extreme magnetic environments. The automatic movement equipped with a Perpetual rotor is protected by a magnetic shield mounted inside the case, allowing resistance to magnetic fields up to 1000 gauss.
To further improve the magnetic resistance of the Rolex Milgauss the movement is equipped with a blue PARACHROM hairspring which in addition to being completely insensitive to magnetic fields is much more shock resistant.
Having previously dealt with Tim, John & Dee by phone, email & post I recently purchased a new Rolex Milgauss at the office in Chiswick. The process could not have been easier. I would not have any concerns recommending them. Thanks guys. Stuart