Magnetic fields are difficult to avoid because they are invisible. It is nevertheless important to know that they are mainly created by magnets, loudspeakers, cellphones, smartphones, magnetic closing systems for refrigerators or cupboards, and magnetic clasps for handbags. To determine whether your mechanical watch is magnetized, place it near a compass and observe whether the needles start to whirl around. If so, your watch is magnetized. In such cases we recommend that you take it to a Cartier boutique, where it will be placed in an inverted magnetic field so as to restore it to its normal working condition.