Perfect for coastal and offshore fishermen who want traditional sonar and CHIRP ClearVü scanning sonar. this transom mount transducer consistently displays clear and crisp fish arches with superior target separation as well as clear definition of structure below the boat. The CHIRP ClearVü element has a power rating of 500 W and operating frequencies of 260/455 kHz. The traditional sonar has a power rating of 600 W and operating frequencies of 50/200 kHz. It also includes a built-in fast response temperature sensor. GT21-TM includes an 8-pin transducer with mounting hardware and installation instructions. Follow the instructions carefully to avoid damaging your boat.