https://www.lowrance.com/lowrance/type/sonar-transducers/hst-wsbl/
This is your transducer.
It fits these “blue connector” units……
The Lowrance 106-72 is compatible with Lowrance HDS-10, HDS-5, HDS-5x, HDS-7, HDS-8, LCX-110C, LCX-111C HD, LCX-112C, LCX-113C HD, LCX-17M, LCX-20C, LCX-25C...