Whether you are about to embark on an expedition to the ends of the Earth or a more subdued day hike, the Garmin GPSMAP 64st has features you will appreciate. This GPS unit’s 2.6″ screen lets you easily navigate through its many features as well as its pre-loaded topographic maps and satellite photos. A 3-axis compass is built-in so you will always know your heading. An altimeter lets you know how far you are above sea level, and can help predict weather trends. The unit runs off two AA batteries or the optional rechargeable NiMH pack.