Garmin GT15M-IH Plastic, In-Hull, Mid-Band CHIRP Transducer - 85-165kHz, 600W, 8-PinThe Garmin GT15M IH Plastic, In Hull, Mid Band CHIRP Transducer is engineered for fiberglass hulls, letting you install the transducer inside the hull instead of on the transom. This setup helps prevent cavitation issues and delivers stable, reliable depth readings at high speeds, making navigation and fishing smoother on fast moving boats. In hull installation designed to minimize cavitation and maximize depth accuracy across hull deadrise angles