Garmin echoMAP 54dv with transducer echo MAP dv series come with built-in 500 W (RMS) traditional HD-ID sonar and DownV scanning sonar capabilities. 5 Hz Internal GPS updates position and heading 5 times per second to make marking and returning accurately to waypoints easier Coordinates the timing of the sonar return with your boat's position and saves digital information for playback on a computer using FREE Homeport planning software. quick-release mount - Cables plug directly into the mount allowing for you to quickly install and remove your device from power and mount. Includes: echo MAP 54dv with U.S. Blue Chart g2, power/data cable, quick-release mount, flush mount, protective cover, GT21-TM transducer (50/200kHz/DownV, 4-pin), trolling motor mount, hardware, documentation