Onboard GPS engine acquires LAT/LON when the unit is activated providing position to within 100 meters. Operating life exceeds 24 hours. Multiple TEST options allow testing battery power, GPS data confirmation, internal circuitry.The smallest, most functional personal Epirb can be easily carried in a pack or pocket. This 406 MHz EPIRB instantly transmits to GEOSAR high-earth orbit satellites so your signal and your position can be quickly routed to the closest appropriate rescue agency.