The GPS III plus improves upon the detailed basemap that made its sister product, the GPS III, so wildly popular, but it adds enhanced cartographic capabilities formerly found only in high-end automotive and marine chartplotting units.
Additional information
The GPS III plus basemap, similar to the map in the GPS III, contains over 10,000 additional towns as well as airport locations and secondary roads within metro areas. The GPS III Plus also comes with an extensive and detailed database of exit information for the federal interstate highway system.