A small transmitter device designed to provide a distress and alerting capacity for use by the general public in life-threatening situations in remote environments, after all other means (e.g., telephone and radio) of notifying search and rescue responders have been exhausted. Although it is not necessary to license a PLB, it is mandatory to register it with the National Oceanographic and Atmospheric Administration (NOAA). Thereby, search and rescue personnel will know who you are, where you are, and whether there are any pre-existing medical conditions that may require treatment when they reach you. PLBs transmit in the 406.0