Marcum LX-9L Lithium Equipped Sonar/Underwater Camera System Fish Finder - Decades of advanced sonar engineering meet wicked underwater wizardry; virtual reality joins aquatic reality, and both live to tell their stories—all on the screen of the same high-powered device. The minds at MarCum Technologies unleash the new LX-9L LiFePO4—a totally dynamic sonar / underwater viewing experience you’ve got to see to believe.