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 mid-band CHIRP traditional sonar (85-165 kHz) and has a power rating of 600 W. It can be used in conjunction with a GT30-TM transducer and an adapter cable so you can maintain depth at high speeds and scanning capabilities at trolling speeds. For installation, follow the included instructions carefully to avoid damaging your boat.