The GSD 25 premium sonar module is a remote network solution that provides outstanding fishfinding and bottom tracking capabilities. It offers dual-channel 1 kW CHIRP, plus Garmin CHIRP DownVü and SideVü sonar scanning for the clearest scanning images on the water. The images sent to your compatible Garmin chartplotter have target details so clear and precise, you can actually distinguish between small and closely spaced fish at key fishing depths all the way down to 5, 000 feet. For the serious offshore sport fisherman, this "one-box" remote network sonar solution provides outstanding fishfinding and depth sounder capabilities for vessels with networked MFD installations. True Dual-Channel 1kW CHIRPCHIRP is the most sophisticated sonar technology available for use by the fishing and boating public. CHIRP is an acronym for Compressed High-Intensity Radiated Pulse. What it means to you is much better target resolution, clarity, and crispness than any other sonar system. Having Garmin true dual 1 kW CHIRP as your traditional sonar allows you to adjust CHIRP frequencies to low/medium, low/high, or medium/high to further optimize your sonar performance. Transducer sold separately. Clearest Scanning Sonar Images on the WaterAdding CHIRP technology to DownVu resolution enhances target separation and clarity of the sonar images of fish and structure that pass below and to the sides of your boat. Built-in to the GPSMAP xsv combos and GSD 25 Premium Sonar Module, it uses 1 transducer for traditional CHIRP HD-ID sonar and CHIRP DownVü and SideVü scanning sonar. Transducer sold separately. Choose a Garmin TransducerThis sonar is so unique Garmin has developed their own proprietary transducers that are specially designed to work with the sonar to provide the very best performance. Compatible Devices: GPSMAP 8000 Glass Helm SeriesGPSMAP 7400/7600 Series Displays DownVu and SideVu sonar scanning Precise fish details down to 5, 000' Transducer sold separately