The Spot Gen4 uses satellite technology which allows you to communicate outside of the boundaries of a phone service. FEATURES: S.O.S. function alerts the GEOS International Emergency Response Coordination Center who will send your GPS coordinates to your local response teams in Australia & New Zealand The S.O.S. button is for those grave or imminent danger situations.. Check-in button allows a pre-programmed text message or an email with your GPS coordinates to your friends or family. Tracking way points can also be integrated into a SPOT Shared Page or Adventure account in near real time. Set up a vibration sensor to tell your SPOT when you are moving or have stopped unintended.