The Humminbird 500 Series offers best-in-class HD screen resolution with timber, rocks, and even fish taking shape on crystal-clear monochrome displays. Down Imaging Sonar with DualBeam PLUS with Switchfire creates detailed images with high-frequency sound waves emitted in ultra-thin slices. The sonar returns from these waves produce a "snapshot" of what's below your boat and are sensitive enough to track a jig down to 70' and separate fish as close as 2.5" apart. Units with internal GPS and built-in UniMap let you pinpoint your location and have an SD card slot for upgrading to LakeMaster or Navionics cartography. 500 Series Fishfinders feature the convenient Tilt and Swivel Disconnect Mounting System. Units measure 7.25"W x 7"H x 4"D.