Airmar SS164 Housing Style Transducer
If a thru-hull flush-style, stainless steel transducer is called for, the 20-degree Tilted Element 556TID-LTD/20 is right for hulls with a deadrise angle of between 16° and 24°. This transducer compensates for deadrise by angling the element inside the housing.
The transducer is labeled with an arrow on top of the housing that should point towards the keel, whether it is installed to port or starboard. This ensures that the tilted element within the housing is given the correct orientation.