I don't recommend them, had one come on my Jon boat and it was junk. Wouldn't produce the correct depth (I.e. show 54' in 4'), and picked up interference from my TM when I turned it on. Plus, I don't receive positive feedback from customers at work with them.
Transducers run $62.99 at Bass Pro, while a new Humminbird Piranhamax150 or even new Cuda runs $79.99. Personally recommend the Piranhamax 170 for $99.99. Dual beam sonar included to provide a wider coverage area. Hope this helps.
-Matt