Garmin GTM 20 Instructions page 7

You can add other FM TMC subscriptions at
any time. Check the Garmin Web site at
www.garmin.com/fmtraffic for other available
services.
Using Traffic Data with Your
Garmin GPS Device
The traffic receiver works with your Garmin
GPS device to show traffic flow and incident
information, and to enable routing around
traffic incidents. Although each GPS device
operates differently, they all provide similar
traffic information.
Register your Traffic Receiver
To register your traffic receiver, go to
http://my.garmin.com.
GTM 20 Instructions