MKR-US2-13 Universal Sonar 2 Adapter Cable Connects Humminbird ONIX Fishfinder. Universal Sonar 2 delivers advanced water temperature sensing and DualBeam PLUS technology for the best view of the waters below. Adapter connects your Humminbird ONIX fishfinder with a Universal Sonar 2 transducer on your trolling motor. Shielded, IP68-rated waterproof connectors are metal tipped to prevent sonar interference.. *200 kHz/83 kHz compatible and only provides traditional 2D sonar