Echonautics BT70MB300-12 300w 95-155kHz Medium CHIRP 12d Tilted Element Bronze THEchonautics BT70MB300 95 155kHz Medium CHIRP 300watts 12 Tilted Element Model: BT70MB300 12 A low profile thru hull CHIRP transducer, that matches vessels deadrise to specific angle. Designed to minimize drag and to perform at high speeds Specifications Function Depth and Temperature frequency CHIRP 95 155kHz Mount style Thru Hull Tilt deadrise 12 tilted element ; for 8 to 15 hull deadrise Material Bronze RMS Power 300 Watts Hole diameter 2. 38 in