Garmin GSD 28 Sonar Module - The depths. Revealed. See what’s down there. Catch what’s down there. Take your sport fishing to extreme depths with a high-powered sonar module with the features you need to improve your chances for success. Garmin RaidReturn Sonar - This high-performance technology provides Garmin's fastest deep-water scrolling sonar with 2 to 6 times the ping rate of Garmin's GSD 26 sonar. This allows captains to make fast and informed decisions based on what is below their boats. xCHIRP Technology - Easily distinguish bait from sport fish with Garmin's clearest traditional sonar fish arches and excellent target separation. Get smooth bottom returns and precise targeting at extreme depths1. Heave Compensation - When the seas get rough, use the MSC 10 external satellite compass (sold separately) to greatly reduce wave and swell from your sonar returns Engineered for offshore sport fishing See sonar faster with Garmin RapidReturn technology Crisp and clear fish targets with xCHIRP technology Excellent target separation with xCHIRP technology Greatly reduce wave and swell from bottom returns with heave compensation Compatibility - This sonar module is compatible with a wide range of Garmin and AIRMAR transducers (sold separately) Retrofitting - The GSD 28 module is ideal for retrofitting boats with existing bare wire transducers Sonar Power- The GSD 28 can output 300 watts to 3 kW at extreme Depths CHIRP Support - The module supports dual-channel CHIRP (up to 3 kW per channel) Operation Range - The GSD 28 sonar module can operate in the 25 to 250 kHz frequency range Built to Last - The GSD 28 is rated for hard marine environments and water resistance with an IPX7 rating. In The Box GSD 28 Power cable Garmin BlueNet marine network cable (6 ft) with legacy network adapter Field installable adapter kit for the Garmin BlueNet network Mounting hardware Documentation