Garmin GT15M-IH Plastic, In-Hull, Mid-Band CHIRP Transducer - 85-165kHz, 600W, 8-Pin [010-12402-00]GT15M IH Plastic, In Hull, Mid Band CHIRP Transducer 85 165kHz, 600W, 8 Pin GT15M IH transducer is ideal for boats that want to install the transducer inside a fiberglass hull and not on the transom where cavitation could cause issues. It can be used with a hull deadrise angle between 0 and 25 degrees and is excellent for boats traveling at high speeds that want to maintain accurate depth readings. The 8 pin transducer with 4 plastic tanks features