Koos - I don't know where wire as small as 28awg wire is used. The X5 connections all terminate back the the X5 course computer that has its own terminal srtip. The Compass has the smallest wires, but runs directly from the compass in one length with no splices back to the course computer terminal strip.

I have used these Euro style terminal strips for other NMEA and power connections for instruments - you can get at Radio Shack

[Linked Image from rsk.imageg.net]