Ah sorry, the one you have is a Through Hull, ie you drill a great big hole in the hull, where as my P79 is an In hull that shoots through the fibreglass and is just bonded in place.
Unfortunately yours wouldn't be much good to me.
I might still be persuaded to sell the P66 though
I looked at the through hull types and decided that I didn't want to risk damaging the transducer on the trailer or when the boat was allowed to dry out on a beach. It also goes against the grain drilling huge holes in the hull.