With its high-sensitivity, WAAS-enabled GPS receiver, eTrex Vista HCx locates your position quickly and precisely and maintains its GPS location in heavy cover. Whether you’re in deep woods or canyons, or just near tall buildings and trees, Vista HCx will help you find your way when you need it the most. The Vista HCx has a built-in electronic compass that provides bearing information even while you're standing still, and its barometric altimeter tracks changes in pressure to pinpoint your precise altitude. You can also use the altimeter to plot barometric pressure over time, which can help you keep an eye on changing weather conditions. Adding maps is easy with Vista HCx's microSD card slot!