If you have a fishfinder that has different frequency settings, I would get the x4. I am able to see my rigger weight down to as deep as i have ever fished it with my new hds7 on 83hrz. No need for a probe to tell you the depth if you can see it on your screen. I fished many weekends on lake ontario with the probe down 140-160ft to find temps, well being able to see it on my fishfinder and get readings from the probe.
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