It does not matter what kind of cluster you have, this is a separate unit with its own modern arm processor. If you install it to a simple cluster with temp only, you have to add wires to it from "the outside".
If you have a big screen FIS already then the cluster has an additinional grey connector at the back and I think you dont need to add extra wires.
The unit is called 3dcolormfd. It is a DIY cluster upgrade for older vw compatible cars.
I'm using it since november 2021 and I like it.
I just noticed that their website has a contact list who can install it:
link