This GARMIN GSD 22 Digital Remote Sounder was in good working condition when it was removed from its vessel 

The GSD 22's digital design provides extraordinary target definition and deep-water performance and allows it to transmit at up to 2 kW, depending on your transducer. The 22 also adjusts gain and transmits power automatically to optimize the returns for shallow water. It can connect to a dual-frequency transducer and works with everything from a standard 500 W transom-mount transducer to a heavy-duty 2 kW thru-hull or in-hull transducer and can reach a depth of up to 5,000 ft (1,524 m).

GSD 22: Powerful eyes in the bottom of your boat