The eTrex Vista Cx is loaded with the same popular features found in the eTrex Vista C, including barometric altimeter, electronic compass, sunlight-readable colour and advanced GPS routing capabilities — all in a waterproof design. Contains the built-in Americas Recreational basemap, and in addition, it comes with a blank 64 MB microSD card for storage of optional map detail. Storing data is easier than ever with Vista Cx's included 64 megabyte (MB) microSD card. Just connect to your computer and load optional MapSource® software to view detailed maps of your surroundings. The card slot is located inside the waterproof battery compartment, so you don't have to worry about getting it wet. You can also use optional preloaded microSD cards with MapSource data for your land and sea excursions. Just insert a MapSource card with detailed street maps, and Vista Cx provides turn-by-turn directions to your destination.