Humminbird 7300211 SW Speed Sensor Uses the most innovative and cutting edge technology Get the most out of your Day trips and getaways The leader in fish finders, depth sounders and GPS Systems Provides digital reading of speed through the water Mounts on boat's transom mount Provides digital reading of speed through the water Mounts on boat's transom mount See product description for full compatibility list Includes 20-foot cable One year limited warranty