I haven't fitted it yet Steve but
I think the answer is nothing - i.e. the 3 white nylon ends don't clip into the housing. Does it matter anyway - if one of more of the cables comes out of the shuttle block everything fails either way.
EDIT: blue text in above para is inaccurate - see post 30.
Iirc, the MGR housing is fairly bendable. Jack's one is extremely rigid - I can't compress it
at all lengthways (by hand), or stretch it.
https://rimmerbros.com/Item--i-GRID001773