From Manufacturer
Combine Garmin's famous navigation technology with anywhere-in-the-world communication and you get the GPSMAP 66i Handheld Navigator and Satellite Communicator. With a paid subscription, you can send and receive texts from anywhere, no cell service needed, via the Iridium global satellite service. If there's a problem, you can send an SOS to the 24/7 GEOS emergency response service, which will dispatch local first responders to your aid and provide interactive support while they're en route.
You'll find your way on preloaded Garmin TOPO maps, augmented by BirdsEye Satellite Imagery that downloads straight to the 66i with no subscription necessary. Challenging routes or environments get a lot easier thanks to the device's support for multiple Global Navigation Satellite Services along with altimeter, barometer, and compass navigation sensors. Pair with your smartphone or device to take advantage of all the route-planning and -sharing capabilities of the Garmin Explore mobile app. And if you have a cell signal, the 66i will use it to pull in Active Weather forecasts, including predictive maps.