The Garmin Rino series is for the outdoorsman who requires GPS technology and 2-way radio service. With 22 channels and up to a 5 mile range, this radio allows you to stay in touch with others in your party. The Rino 610 comes with a built-in worldwide basemap and contains 2000 waypoint capacity, allowing you to mark your favorite hunting, hiking and fishing spots. With 1.7 GB of internal memory, you also have the power to download additional detailed maps from the Garmin library . You'll never have to worry about wet weather ruining your unit. With its weatherproof design, the Rino 610 will stay dry and functional and is submersible up to 1 meter for 30 minutes. The Rino 610is best powered by 4 lithium AA batteries and has an approximate runtime of 18 hours on one set. This handy unit also features hunt/fish calendars and sun/moon information, to give you the best data for your hikes, hunts and fishing trips. With Rino's position reporting feature, you can let your friends know exactly where you are. The Rino units also are equipped with standard FRS/GMRS radio, which allows you to communicate with any compatible radio out there. The combination of a quad helix antenna, WAAS-enabled GPS tracking and HotFix satellite location, you will be able to navigate even in the deepest of canyons or thickest of brush.