Magnetic Mastery Originally developed in the 1950s for scientists and engineers, the Rolex Milgauss was designed to resist magnetic interference up to 1, 000 gauss. Its distinctive lightning-bolt seconds hand and green sapphire crystal have made it one of the most recognisable and unconventional models in the Rolex catalogue. Engineered for Precision This 2015 reference features a black dial housed in a 40mm Oystersteel case with a smooth bezel. Powered by the calibre 3131 automatic movement, it offers a 48-hour power reserve and is fitted with an Oyster bracelet featuring Easylink extension and Oysterclasp. A bold and technical timepiece with a unique legacy.