Mitchell,
The Helix 7 must be a G2N model the N means it can be networked. The Y splitter allows you to run two transducers on the same unit. Typically this involves a high speed transducer and the SI or DI transducer if your Helix has that capability.
To network the unit you only need to run an ethernet cable from the 5 port switch to the unit. There is a ethernet adabtor cable (AS EC QDE) required to connect the ethernet cable to the proper connector for the Helix 7.
You are e awesome thank you! That literally answered what I needed.