The current version for US is v704.xxxx which only works with the new units, more specifically NavCore 7.
Below that version is v675.xxxx.
You can check your version by tapping the bottom right corner of the navigation screen, then tap version. At this screen, you should see your map version here.
Below that version is v675.xxxx.
You can check your version by tapping the bottom right corner of the navigation screen, then tap version. At this screen, you should see your map version here.