Wood2008

Keep in mind that these boxes will work while the car is still, but once in motion you will loose the signal. Anything over about 5MPH.

The mini USB on the back is for use with the TMC live traffic module. The part number is GTM10. It is the terrestrial version of live traffic. You can see the coverage area on Garmin's web site. The 5120 doesn't update using this jack the updates for mapping are done via disc. ( put in the disc and it rewrites the memory)