With a 2.6 cm (2.2 inch) full colour sunlight-readable screen along withe ability to accept additional maps via a Micro SD slot the e Trex 20 is a truly versatile GPS for the great outdoors Comes with a preloaded worldwide shaded basemap making it easier than ever to know where you are & where you are headed next Compatible with City Navigator & Discoverer Ordnance Survey mapping 1.7 GB internal hard drive allows the use of Garmins Birdseye select mapping service so you can select the coverage you need 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