With the addition of a 3-axis tilt compensated electronic compass barometric alimeter & wireless connectivity the e Trex 30 is all you could ask for in a handheld outdoor GPS A 2.6 cm &40;2.2 inch&41; full colour sunlight-able screen & a preloaded worldwide shaded basemap making it easier than ever to know where you are & where you are headed next Micro SD card slot allows easy use of Garmin City Navigator & Discoverer Ordnance Survey mapping to the unit 1.7 GB internal hard drive allows the use of Garmins Birdseye select mapping service so you can select the coverage you need Wireless connectivity allows the e Trex 30 to be used with ANT fitness sensors such as heart rate monitors Intuitive navigation screens making it easy to find the features you want High-sensitivity EGNOS-enabled Hotfix GPS receiver enables a fast & reliable satellite connection Supports paperless geocaching via Garmins Opencaching service Waterproof to IPX7 standard Runs off 2 x AA batteries giving up to 25 hours use