I have a XE75 mesh with three modules all linked by backhaul and working well

There are a couple of areas of the house not covered ... one inside and one outside.  The inside room is not large so needs a smaller unit.

I need to backhaul them because the house is well insulated and connecting modules by wifi therefoee doesnt work very well and costs alot of bandwidth

Which TP / Deco modules are compatible with the mesh I have ?

Thanks