Black Diamond did extensive work on testing common electronics and how they can interfere with beacons in search mode. Common culprits of EMI include smart phones, radios, smart watches, satellite communication devices, snowmobiles, heated gloves, and even ambient conditions like nearby high voltage power lines can all interfere with your beacon in various degrees of severity. We would strongly encourage careful consideration and testing of the personal devices you choose to carry into the backcountry, and how they might potentially interfere with a beacon search.