Want to use your echo series fishfinder in more than one vessel. A second transducer can make the process a lot easier. It comes with all of the hardware you need to mount on your transom or trolling motor. Echo 100 is a single-beam fishfinder. When using this transducer with echo 100 it will only transmit and receive at the 200 kHz frequency.

Garmin Dual Beam Transom Mount Transducer
$49.03