DESC: nüvi 550 features driving, walking, bicycling and boating modes which customize your nüvi specifically for your method of travel. This portable hybrid combines the advanced navigation features and large, color display found in automotive units with the durability of an outdoor handheld. Sleek and slim, you can slip nüvi 550 into your pocket or backpack. The user-replaceable, rechargeable lithium-ion battery lets nüvi navigate you on roads or off.