The Rolex Milgauss was originally introduced by Rolex in 1956 as an anti-magnetic watch specifically for folks working in industrial power plants, medical facilities, and laboratories. The idea behind the Rolex Milgauss watch is that it can withstand electromagnetic fields up to 1,000 gauss. The Rolex Milgauss can withstand magnetic fields because of a amagnetic alloy (Parachrom-Blu) hairspring and a faraday cage which protects the watches movement.
The Milgauss was reintroduced by Rolex in 2007 in three versions: a white dial and black dial version with standard sapphire crystal glass, and a GV edition with green tinted sapphire crystal. My favorite feature is the orange lightning-bolt second hand. More pictures and video after the break.