Humminbird TCR ID-1 Operation Manual page 16

USING THE TCR ID-1
HOW SONAR WORKS
Compact, High-Definition Sensor.
To send and receive this higher-frequency signal, we developed a new High-Definition
Sensor. You can immediately see the difference between our 455KHz Sensor and older
200KHz transducers. This unique new Sensor makes bulky low-definition transducers a
thing of the past.
Our new Sensor is so compact, it's a snap to install. It's designed for superior high-
speed performance, and because of its small size you'll have less problem with drag,
turbulence, or rooster-tails. This new Sensor is actually less likely to be damaged by
debris, yet performs with all the accuracy you expect from Humminbird.