StreetPilot 7500 Portable Navigator Monitor traffic tie-ups with the addition of an optional FM TMC traffic receiver. By adding traffic services and a receiver/antenna to your StreetPilot 7500 Portable Navigator, it notifies you of accidents, road construction, and weather-related traffic delays before they are encountered. View real-time weather conditions with the optional GXM 30 smart antenna and a XM NavTraffic subscription. It features internal MP3 player, XM radio, and audio books. Music can be loaded onto an SD card and is drag-and-drop easy-no special software is required. It also includes dead reckoning sensors to track your vehicle's course when your GPS signal is blocked for example in urban areas or tunnels. If you lose GPS coverage in areas with tall buildings or tunnels, the StreetPilot 7500 Portable Navigator keeps on navigating. Minimal installation is required for the dead-reckoning feature.