Quote Originally Posted by hays47 View Post
I believe Mr Greg is wrong the transducer that came with my 981 and 987 C was a XHS 9-
160 T.

To differentiate when the 997C was released Humminbird worked HDSI into the part number but 180T was on the tail end of that number.
Oops! Part number all discombooberated...
XHS-9-Si-160-T is the correct part number for the older 262/455kHz Si transducer.