B619. Personally I don’t care about anything but traditional sonar. It’s 77 and 200 frequency and you can run a split screen. Bronze and a temp ducer. What else could I possibly need. It was time consuming to do alone. A lot of in and out, but painfully fun. I ran the line with surgical lube in the wire chase under the port side. Easy as 1,2,3 since I used the old wire as a pull. I got an MMSI number and linked my vhf and 840xs. Now if I need to leave my boat at least someone may find me.