Magnetic fields have long been the mechanical watch’s arch enemy. In 1956 Rolex declared war on them when it launched the Oyster Perpetual Milgauss designed to withstand up to 1000 gauss (hence the name) whilst being reliable and accurate. Different versions of the timepiece have appeared over the years and the 2014 model comes in a 40mm steel case with a green sapphire crystal screen housing the automatic 3131 calibre. Made in-house by Rolex and COSC-certified, this model is protected by an internal shield and made up of paramagnetic components. It is therefore unaffected by magnetic fields and brings to life time functions and a 48-hour power reserve. The indices and hour and minute hands are coated in Chromalight – the blue-toned luminescent material designed by Rolex – whilst the orange minute track and lightning-shaped second hand stand out on the electric blue dial. Price: 7800 CHF