A pre-expanded cover assembly unit for covering an electrical connection between first and second cables includes a cover assembly in a folded state including an elastomeric outer sleeve defining a cable passage to receive the electrical connection. The outer sleeve includes an intermediate section and first and second outer sections. The first outer section is folded at a first annular fold and is on the intermediate section and/or the second outer section. The cover assembly includes a first retention layer between the intermediate section and the first outer section. The cover assembly includes a first friction reducing layer between the first retention layer and the first outer section. The cover assembly unit includes a removable holdout mounted within the outer sleeve. The cover assembly is movable from a folded state to an unfolded state by sliding the first outer section in a first axial direction away from the intermediate section.