Rolex's antimagnetic watch designed for scientists and launched in 1956 is the Milgauss.
The name combines mille, meaning one thousand in French, with gauss, a unit used to describe magnetic-field strength. Rolex designed the watch to resist magnetic fields of up to 1,000 gauss, which could disrupt the balance spring and other components of a mechanical movement.
The original Milgauss used a soft-iron inner shield around the movement and featured a distinctive lightning-bolt seconds hand. It was aimed at people working near strong magnetic equipment, including laboratory and power-industry personnel.
The model disappeared from Rolex's catalogue in 1988 and returned in 2007. Its colorful seconds hand and, on some versions, green-tinted crystal became recognizable modern traits.