The NAV ONE unit is a specialized, portable navigation system for use in vehicles. It provides turn-by-turn route guidance by combining: A Global Positioning System (GPS) receiver to detect position . A detailed map of the 48 contiguous states, Hawaii and major metropolitan areas in Canada. Plug and Go functionality. REAL-TIME TRAFFIC INFORMATION Includes Traffic Receiver and Comes with a 90 Day FREE Subscription. Avoid Traffic Jams.