What does "door kits" mean?
If all the components are supplied to site from ONE SOURCE (one legal entity) then this is qualified as a doorset.
“Door kit” is a UK term which describes a door and frame delivered in kit form, with some or all of its hardware, eventually supplied on different days.
If some components are supplied from other sources, then it falls under the same rules as a door assembly.
“Doorsets” and “Door kits” can be CE marked, but “Door assemblies” can’t.