Increase your probability of survival at sea with the multiple built-in redundancies of the GlobalFIX V4 marine distress EPIRB. Upon activation, the GlobalFIX V4's robust Internal GPS accurately fixes your exact location, broadcasting your coordinates via a powerful 406 MHz distress signal to Search and Rescue forces worldwide. In the absence of GPS data, orbiting Cospas-Sarsat satellites can accurately triangulate your position using the 406 MHz signal alone. A 121.5 MHz homing signal further guides searchers to your exact position. FCC Approved.