Bluetooth Low-Energy (BTLE) wirelessly pairs goTenna to your smartphone within approximately 20 feet. Long-range radio waves (151-154 MHz) radios and depends on terrain and elevation; up to 1 mile in urban settings and 4 miles in most outdoor terrain
Use your iOS or Android phone to send texts & share GPS locations when there's no cell coverage or wifi available
goTenna creates its own off-grid network with other goTenna users in the area
Send private 1-to-1 & group chats or broadcast to all users nearby
Free goTenna app includes free, detailed offline maps for any region in the world
Sold in pairs
Really it's a way to use your mobile devices without service but great for when you are traveling in remote places.