Personal Locator Beacon or "PLB" directs Search and Rescue teams to your exact location. They are Cospas-Sarsat standard and FCC approved 406MHz 50-channel integral GNSS receiver (GPS, Galileo, GLONASS). Once activated these units will operate for a minimum of 24 hours continuous operation. Buoyant if used with included flotation pouch and waterproof to 30 feet, operating at temperatures down to -20°C. Other features: includes lanyard and universal pouch, SOS LED flash light, unit has a 6 year battery storage life. A must have device for your grab bag.