With the included CHIRP 77/200kHz transducer and CHIRP DownVü scanning sonar, Garmin's Striker 4dv Sonar/GPS Combo provides greater sensitivity, improved target resolution and superior noise reduction on the water for clearer, more easy-to-see images of both baitfish and gamefish targets. Plus, you can mark hotspots so you can return to them later and even share your favorite spots with other Striker and echoMAP combos with built-in GPS. Includes sonar history rewind. Also features Smooth Scaling™ depth-range adjustments and built-in flasher. 3.5" color display sports intuitive controls for customizing your setup.