Ok, Thanks. I plan to upgrade from a FCV271 to the BBFF3 coupled to a VX2. I'm assuming I have a 50B-9B installed as that's what's indicated on a sticker above the connector socket on the back of the FCV271. The transducer is eight to ten inches long, solid brass and has two circular sensor inserts in it. It's embedded in a fairing block protruding from the hull. If there's a way to confirm that it is in fact a 50B-9B please let me know how to do so. Otherwise, I'm buying the BBFF3 and VX2, hooking it all up and assuming it will all work -as the FCV271 and installed transducer are currently working.