Garmin GT15M-THGarmin GT15M TH GT15M TH transducer is perfect for fishermen who want clear bottom definition under the boat as well as crisp, clear and wide fish arches with excellent target separation to depth up to 1000 feet. The 8 pin transducer features mid band CHIRP traditional sonar (85 165 kHz) and has a power rating of 600 W. The bronze thru hull housing and stem makes it ideal for wooden fishing boats. Follow the included installation instructions