chappy64, if you are talking about the uniplug transducer that comes with the ice pack; it is supposed to work with blue plug units but you have to get the uni to blue plug adapter cable. I have the new Elite 5 HDI (blue plug unit) on my boat and bought the ice pack bag kit to use it on hard water but did not use the uniplug transducer, instead I bought the blue plug ice transducer to plug directly into the 5 HDI, so I cannot verify that it does work, but I still have it. But the uniplug transducer is in the transducer selection list in the menus on the 5 HDI.