A replacement Remote Sonar Sensor for your SMARTCAST Wireless Fishfinder. Simply set your display unit to Channel A & start fishing. Ultra-wide 90 degree sonar beam Fully waterproof Typically lasts 400 hours of in-the-water usage Wet Switch™ technology maximizes battery life by automatically shutting down when Remote Sonar Sensor is out of the water Depth capability of 100ft. Operating frequency of 125 k Hz Code: F-TRANSDUCER