For ION or ONIX unit in box there is the head and some cables for power for CP modèles!
For such with sounder in is ad tranducer can be choose at the order (2D or side)
For sonar box only the box and power cable (hope cable between head!) Transducer must be choose, can be 2D one as TM from Airmar, side transducer or if lucky a chirp one!