Italian speedo cable drive size

Hi,
The square profile on the end of the cable that fits into the speedo housing has sides that are 2mm wide. This seems too small for the square socket I can see inside the speedo.
How big should the end of the speedo cable be? It looks like it should be about 2.5mm square.
Thanks!
The square profile on the end of the cable that fits into the speedo housing has sides that are 2mm wide. This seems too small for the square socket I can see inside the speedo.
How big should the end of the speedo cable be? It looks like it should be about 2.5mm square.
Thanks!