>>96790651
>>96790750
While the socket used by space marine backpacks is supposed to be compatible all the way to primaris, the backpacks were also released along certain armour marks. Like the original Mars one used by MkII and MKIII.
The mkIV backpack was the default model used in MkIV onwards until M36-7 when it began to be replaced with the one currently seen in 40k tacticals.
Phaeton was an offshot backpack used mostly in mkV and MKI suits, also based in MKVI tech themselves

The jump packs are another matter, but they usually were modified or based in the regualr backpack models. There's pretty much a jp variant for each one.

>no idea how mkV jump packs are even supposed to look
like pic related, it's based in the same Phaeton design