That is the main product line. Helix replaced the units that used to have number names.
In a Side Imaging model, the Helix 12 CHIRP SI GPS replaced the 1199ci HD SI Combo.
There are three series of Helix 7 (7" diagonal display 16:9 ratio).
The same technology:
Helix 7 SI GPS=first generation--discontinued
Helix 7 CHIRP SI GPS G2=current model standalone unit
Helix 7 CHIPR SI GPS G2N=current model that is networkable
There are Helix 5 models=5" screen
Helix 7 models=7" screens
Helix 9 models=9" screens
Helix 10 models=10" screens
Helix 12 models=12" screens
The top of the line model is the discontinued ONIX and its replacement SOLIX.
They are more sophisticated and have touch screens.
Humminbird Helix 12 CHIRP SI, 1198c SI, 1198c SI, ONIX 10 SI NT, Helix 7 CHIRP SI GPS G2, SOLIX 12 SI, 360, RC-1