Garmin GTM 20 Instructions page 5

Connecting an External Antenna
An external antenna may be included in the
product box to increase signal range. To
purchase an external antenna, go to
http://buy.garmin.com.
1. Connect the external antenna to the
GTM 20.
External antenna
connector
2. Use the attached suction cups to route
the external antenna on the windshield
vertically, if possible.
Before mounting the traffic receiver, see the Important
Safety and Product Information guide included with your
GPS device for information about laws pertaining to
windshield mounting.
GTM 20 Instructions
External antenna