Through Hull Transducer

[eggsuckindog]

I have one that was on the boat when I got it, it now has a Lowrance 498 depth finder with a transom mount ducer. I would like to indentify the unit and maybe try and use it since Airimar makes almost all of them maybe it will work with the proper connector. It looks like a standard ducer that I have seem a hundred times, football shape with the round black sender, any ideas where a number might be??