Garmin eTrex30 GPS Rugged handheld navigator with preloaded worldwide relief basemap and 2.2-inch color display WAAS-enabled GPS receiver with HotFix and GLONASS support for fast positioning and a reliable signal Built-in 3-axis electronic compass always shows your heading; barometric altimeter pinpoints your precise altitude Compatible with topographic, marine, and road maps--TOPO U.S. 24K, BlueChart g2, City Navigator, etc. Powered with two AA batteries; waterproof to IPX7 standards for protection against splashes, rain, etc.