Angled Puck Transducer - Inside Hull Transducers mount to the inside of most fiberglass boat hulls and transmit the sonar signal through the hull. On hulls with a deadrise less than 15 degrees, a flat bottom transducer should be used. For angles greater than 15 degrees, an angled transducer is recommended to assure the sonar signal travels downward. Description: Single/Dual Puck Angled Transducer. For Use With: Piranha 1, Piranha 2, Piranha 3, Piranha 4, Piranha 5, Matrix 15, Matrix 17, Matrix 25, Matrix 27, Matrix 55, Matrix 65, Matrix 67, Matrix 97, FF515, FF535, FF565.