Garmin's GT15M-IH In-Hull Mid-band CHIRP Transducer provides accurate depth readings even at high speed. Ideal for watercrafts that want to install the transducer inside a fiberglass hull and not on the transom. It can be used with a hull deadrise angle between 0 and 25 degrees and is excellent for watercrafts traveling at high speeds. In-Hull installation, no need to drill through the vessel; no drag. The 8-pin transducer with 4 plastic tanks features mid-band CHIRP traditional sonar (85-165 kHz) and has a power rating of 600 W. Requires Garminâ€ ECHOMAPâ„¢ UHD 72sv or 62cv GPS.