It's the ultimate navigational tool. eTrex Vista has enough map detail to help you get out of town, an electronic compass to keep you on course, and a barometric altimeter to record the details of your trek. The Vista is designed to provide precise GPS positioning using WAAS. It also boasts an internal memory of 24 MB (Vista), enough to store 20 routes (50 HCx), 1000 waypoints, and 10 tracks or downloaded Mapsource maps for greater detail. The Vista HCx adds high-sensitivity receiver, color screen, and a microSD card port. That's a ton of utility in a unit weighing a mere 5.3 oz (5.5 oz HCx)!