I don't know what transducers some of the guys with converted units are using but be warned there are 2 different cristal materials used in transducers. The normal ones are used because they are cheap but flake out in the cold. I tried to convert a normal one over and it would start to loose resolution after a while in the cold, pull it out of the hole in -20 to land a fish and whe you get it back down it would not even see bottom untill it warmed back up. The ones used in actual ice flashers are more expensive and are not affected by the cold.
At 300 bucks for a case and a transducer they are no friend of mine. That's outrageous! The price of electronics in general is outrageous but that case price is totally out of whack. Last time I looked they were about half of that.