Description 2015 Case: stainless steel, 40 mm diameter Bracelet: stainless steel Oyster Dial: green with orange lightning bolt hand Reference number: 116400 Serial number: 7HX67715 Caliber: 3131, automatic Accessories: presentation box, outer packaging, seal tags, extra link, product literature and guarantee card Gross weight approx. 153.2 g Movement not tested Note: The Rolex Oyster Perpetual Milgauss is a wristwatch model introduced by Rolex in 1956 with model number 6541. The Milgauss was designed to meet the demands of the scientific community working around electromagnetic fields. Hence, the name of the watch model is derived from the French mille, which means one-thousand, and gauss, the unit of a magnetic field. The first of its kind, it is capable of withstanding magnetic fields of up to 1,000 gauss and became known for being worn by scientists at the European Organization for Nuclear Research (CERN) in Geneva. Its resistance to magnetic interference stems from a shield inside the case