The down looking sonar built into the Side Imaging units is an advanced Dual Beam technology 200/83 khz (20/60 degrees of coverage) that provides great detailed bottom definition from the narrow beam and great coverage for fish and structure from the wide beam. Most competitive models only use single beam technology, which limits their coverage to find structure and fish.  In addition, all of our Side Imaging products also include SwitchFire Sonar and Down Imaging Sonar which provides even better details of the bottom compared to traditional down looking sonar.