This can occur when a watch is subjected to a magnetic field. A magnetic field can emate from a variety of different sources in day to day life. Computer hard drives, medical equipment, large speaker systems, refrigerator doors, magnetic tablet cases, mobile phones, magnetic catches on handbags to name a few can all emit magnetic fields. Magnetism may lead to excessive rate gain which can cause a watch to run fast or stop entirely. Magnetic fields do not cause permanent damage and minor intervention only is required to return your Bremont to it’s usual excellent standard.